extend-core
Advanced tools
Extend Core is a TypeScript library that provides a collection of utility functions to extend and enhance the functionality of JavaScript's core objects, such as Array, String, Object, Date, Number, JSON, File, Buffer, Function, and Promise. It offers a w
A comprehensive TypeScript library that extends native JavaScript prototypes with useful utility methods. This library provides additional functionality for Arrays, Booleans, Dates, Functions, Numbers, Objects, Strings, and more.
via npm
npm install --save extend-core
via yarn
yarn add extend-core
Simply import the library and start using the extended methods:
/* for load all prototypes */
import 'extend-core';
/* for load only array prototypes */
import 'extend-core/array';
/* for load only array .pull prototype */
import 'extend-core/array/pull';
// Array methods
const numbers = [1, 2, 3, 4, 5];
console.log(numbers.average()); // 3
console.log(numbers.chunk(2)); // [[1, 2], [3, 4], [5]]
// String methods
const text = 'hello world';
console.log(text.capitalize()); // 'Hello world'
// Date methods
const today = new Date();
console.log(today.isToday()); // true
You can use the library directly in the browser via unpkg or jsDelivr:
via unpkg
<script src="https://unpkg.com/extend-core@1.0.0/index.js"></script>
<script>
console.log(isBoolean(true)); // true
</script>
via jsDelivr
<script src="https://cdn.jsdelivr.net/npm/extend-core@1.0.0/index.js"></script>
<script>
console.log("abcdef".chunk(2)); // ['ab','cd','ef']
</script>
After including the script, the functions will be available globally.
Array manipulation and utility functions.
average() - Returns the average of all numeric elements
[1, 2, 3].average(); // 2
[1, 'a', 2].average(); // 1.5
[].average(); // NaN
chunk(size) - Splits the array into chunks of specified size
const arr = [1, 2, 3, 4, 5];
console.log(arr.chunk(2)); // Output: [[1, 2], [3, 4], [5]]
console.log(arr.chunk(3)); // Output: [[1, 2, 3], [4, 5]]
first() - Returns the first element of the array
const arr = [1, 2, 3];
console.log(arr.first()); // Output: 1
const emptyArr: number[] = [];
console.log(emptyArr.first()); // Output: undefined
clone() - Creates a shallow copy of the array
const arr = [1,2,3];
const copy = arr.clone();
console.log(copy); // [1,2,3]
console.log(copy === arr); // false
difference(values) - Returns elements that are in the first array but not in the second
[1, 2, 3, 4].difference([2, 4]); // [1, 3]
drop(n) - Removes the first n elements
[1,2,3,4].drop(2); // [3,4]
dropLast(n) - Removes the last n elements
[1,2,3,4].dropLast(2); // [1,2]
flatten(depth?) - Flattens nested arrays up to the specified depth
[1, [2, [3]]].flatten(); // [1, 2, [3]]
[1, [2, [3]]].flatten(2); // [1, 2, 3]
flattenDeep() - Recursively flattens all nested arrays
[1, [2, [3, [4]]]].flattenDeep(); // [1, 2, 3, 4]
intersection(otherArray) - Returns common elements between arrays
[1,2,3].intersection([2,3,4]); // [2,3]
['a','b'].intersection(['b','c']); // ['b']
isEmpty() - Checks if the array is empty
[].isEmpty(); // true
[1, 2, 3].isEmpty(); // false
last() - Returns the last element of the array
const arr = [1, 2, 3];
console.log(arr.last()); // Output: 3
const emptyArr: number[] = [];
console.log(emptyArr.last()); // Output: undefined
max() - Returns the maximum value
[1, 2, 3].max(); // 3
[1, 'a', 2].max(); // 2
[].max(); // -Infinity
median() - Returns the median value
[1, 2, 3].median(); // 2
[1, 'a', 2, 4].median(); // 2
[1].median(); // 1
[].median(); // NaN
min() - Returns the minimum value
[3, 1, 4, 1, 5].min(); // 1
[1, 2, 'a', 3].min(); // 1
['a', 'b', 'c'].min(); // Infinity
[].min(); // Infinity
mode() - Returns the most frequent value
[1, 2, 2, 3].mode(); // [2]
[1, 1, 2, 2, 3].mode(); // [1, 2]
[1].mode(); // [1]
[].mode(); // []
padEnd(length, value) - Pads the array to a specified length
[1,2].padEnd(4, 0); // [1,2,0,0]
padStart(length, value) - Pads the array to a specified length from the start
[1,2].padStart(4, 0); // [0,0,1,2]
partition(predicate) - Partitions the array based on a predicate
[1,2,3,4].partition(x => x % 2 === 0); // [[2,4],[1,3]]
peek(position?) - Returns the first or last element without removing it
[1,2,3].peek(); // 3
[1,2,3].peek('first'); // 1
pluck(keyOrPath) - Extracts a property from each object in the array
[{a:1}, {a:2}].pluck('a'); // [1,2]
[{a:{b:1}}, {a:{b:2}}].pluck('a.b'); // [1,2]
product() - Returns the product of all numeric elements
[1,2,3,4].product(); // 24
pull(...values) - Removes specified values from the array
const arr = [1, 2, 3, 4, 5, 2];
arr.pull(2); // arr is now [1, 3, 4, 5]
const arr2 = [1, 2, 3, 4, 5];
arr2.pull((n) => n % 2 === 0); // arr2 is now [1, 3, 5]
random() - Returns a random element from the array
const arr = [1, 2, 3];
console.log(arr.random()); // Could be 1, 2, or 3
const emptyArr: number[] = [];
console.log(emptyArr.random()); // Output: undefined
reverseCopy() - Returns a reversed copy of the array
[1,2,3].reverseCopy(); // [3,2,1]
const arr = [1,2,3];
arr.reverseCopy(); // [3,2,1], arr remains [1,2,3]
rotate(steps) - Rotates the array by a specified number of positions
[1,2,3,4].rotate(1); // [4,1,2,3]
[1,2,3,4].rotate(-1); // [2,3,4,1]
shuffle() - Randomly shuffles the array
const arr = [1, 2, 3, 4, 5];
arr.shuffle(); // e.g., [3, 5, 1, 4, 2]
sortBy(key?, order?) - Sorts the array by a specified property or function
[3,1,2].sortBy(); // [1,2,3]
[{a:2},{a:1}].sortBy('a'); // [{a:1},{a:2}]
[{a:2},{a:1}].sortBy('a','desc'); // [{a:2},{a:1}]
[{x:2},{x:1}].sortBy((item,i,array) => item.x + i, -1); // [{x:2},{x:1}]
std() - Returns the standard deviation
[2,4,4,4,5,5,7,9].std(); // 2
sum() - Returns the sum of all numeric elements
[1, 2, 3].sum(); // 6
[1, 'a', 2].sum(); // 3
take(n) - Returns the first n elements
[1,2,3,4].take(2); // [1,2]
takeLast(n) - Returns the last n elements
[1,2,3,4].takeLast(2); // [3,4]
tap(fn) - Executes a function and returns the original array
[1,2,3].tap(arr => console.log(arr)).map(x => x*2);
unique(keyFn?) - Returns unique elements from the array
[1,2,2,3,1].unique(); // [1,2,3]
[{a:1},{a:1}].unique(item => item.a); // [{a:1}]
variance() - Returns the variance of numeric elements
[2,4,4,4,5,5,7,9].variance(); // 4
zip(...arrays) - Combines multiple arrays into an array of tuples
[1,2,3].zip(['a','b','c']); // [[1,'a'], [2,'b'], [3,'c']]
[1,2].zip(['a','b','c'], ['x','y']); // [[1,'a','x'], [2,'b','y'], [undefined,'c',undefined]]
Boolean operations and utilities.
and(other) - Performs AND operation with another boolean
(true).and(true); // true
(true).and(false); // false
isTrue() - Checks if the value is exactly true
(true).isTrue(); // true
(false).isTrue(); // false
isFalse() - Checks if the value is exactly false
(true).isFalse(); // false
(false).isFalse(); // true
nand(other) - Performs NAND operation
(true).nand(true); // false
(true).nand(false); // true
nor(other) - Performs NOR operation
(false).nor(false); // true
(true).nor(false); // false
or(other) - Performs OR operation with another boolean
(true).or(false); // true
(false).or(false); // false
toBit() - Converts boolean to bit (0 or 1)
(true).toBit(); // "1"
(false).toBit(); // "0"
toggle() - Toggles the boolean value
(true).toggle(); // false
(false).toggle(); // true
toNumber() - Converts boolean to number
(true).toNumber(); // 1
(false).toNumber(); // 0
toString() - Converts boolean to string
(true).toString(); // "true"
(false).toString(); // "false"
xor(other) - Performs XOR operation with another boolean
(true).xor(false); // true
(true).xor(true); // false
Buffer utilities and conversions.
toBase64() - Converts buffer to base64 string
const buf = Buffer.from('hello');
buf.toBase64(); // "aGVsbG8="
toUint8Array() - Converts buffer to Uint8Array
const buf = new ArrayBuffer(4);
const arr = buf.toUint8Array(); // Uint8Array(4) [0,0,0,0]
Date manipulation and utility functions.
addDays(n) - Adds n days to the date
const d = new Date();
d.addDays(5); // 5 gün ekler
isToday() - Checks if the date is today
new Date().isToday(); // true
addHours(n) - Adds hours to the date
const d = new Date('2025-09-17T12:00:00');
d.addHours(3); // 2025-09-17T15:00:00
addMinutes(n) - Adds minutes to the date
const d = new Date('2025-09-17T12:00:00');
d.addMinutes(15); // 2025-09-17T12:15:00
addMonths(n) - Adds months to the date
addSeconds(n) - Adds seconds to the date
const d = new Date('2025-09-17T12:00:00');
d.addSeconds(30); // 2025-09-17T12:00:30
addWeeks(n) - Adds weeks to the date
addYears(n) - Adds years to the date
clone() - Creates a copy of the date
const d1 = new Date('2025-09-17');
const d2 = d1.clone();
d1 === d2; // false
dayName() - Returns the day name
dayOfYear() - Returns the day of the year
const d = new Date('2025-01-15');
d.dayOfYear(); // 15
differenceInDays(otherDate) - Calculates difference in days
differenceInMonths(otherDate) - Calculates difference in months
differenceInYears(otherDate) - Calculates difference in years
diffInDays(otherDate) - Calculates difference in days
new Date('2025-09-17').diffInDays(new Date('2025-09-20')); // -3
diffInHours(otherDate) - Calculates difference in hours
new Date('2025-09-17T12:00').diffInHours(new Date('2025-09-17T08:00')); // 4
diffInMinutes(otherDate) - Calculates difference in minutes
new Date('2025-09-17T12:00').diffInMinutes(new Date('2025-09-17T11:30')); // 30
diffInMonths(otherDate) - Calculates difference in months
new Date('2025-09-17').diffInMonths(new Date('2025-06-17')); // 3
diffInSeconds(otherDate) - Calculates difference in seconds
new Date('2025-09-17T12:00:30').diffInSeconds(new Date('2025-09-17T12:00:00')); // 30
diffInYears(otherDate) - Calculates difference in years
new Date('2025-09-17').diffInYears(new Date('2020-09-17')); // 5
endOfDay() - Returns end of day
endOfMonth() - Returns end of month
endOfYear() - Returns end of year
format(fmt) - Formats the date according to the given format string
const d = new Date('2025-09-17T12:30:45');
d.format('YYYY-MM-DD'); // "2025-09-17"
d.format('DD/MM/YYYY HH:mm'); // "17/09/2025 12:30"
isAfter(otherDate) - Checks if date is after another date
const d1 = new Date('2025-09-19');
const d2 = new Date('2025-09-18');
d1.isAfter(d2); // true
isBefore(otherDate) - Checks if date is before another date
const d1 = new Date('2025-09-17');
const d2 = new Date('2025-09-18');
d1.isBefore(d2); // true
isBetween(startDate, endDate) - Checks if date is between two dates
const d = new Date('2025-09-17');
d.isBetween(new Date('2025-09-16'), new Date('2025-09-18')); // true
isFuture() - Checks if date is in the future
new Date('2030-01-01').isFuture(); // true
isLeapYear() - Checks if year is a leap year
new Date('2024-01-01').isLeapYear(); // true
isPast() - Checks if date is in the past
new Date('2020-01-01').isPast(); // true
isSameDay(otherDate) - Checks if dates are the same day
const d1 = new Date('2025-09-17');
const d2 = new Date('2025-09-17');
d1.isSameDay(d2); // true
isSameMonth(otherDate) - Checks if dates are the same month
const d1 = new Date('2025-09-17');
const d2 = new Date('2025-09-01');
d1.isSameMonth(d2); // true
isSameYear(otherDate) - Checks if dates are the same year
const d1 = new Date('2025-09-17');
const d2 = new Date('2025-01-01');
d1.isSameYear(d2); // true
isTomorrow() - Checks if date is tomorrow
const d = new Date();
d.setDate(d.getDate() + 1);
d.isTomorrow(); // true
isWeekday() - Checks if date is a weekday
new Date('2025-09-17').isWeekday(); // true (Wednesday)
isWeekend() - Checks if date is a weekend
new Date('2025-09-20').isWeekend(); // true (Saturday)
isYesterday() - Checks if date is yesterday
const d = new Date();
d.setDate(d.getDate() - 1);
d.isYesterday(); // true
monthName() - Returns the month name
quarter() - Returns the quarter
const d = new Date('2025-05-10');
d.quarter(); // 2
startOfDay() - Returns start of day
startOfMonth() - Returns start of month
startOfYear() - Returns start of year
subtractDays(n) - Subtracts days from the date
subtractHours(n) - Subtracts hours from the date
const d = new Date('2025-09-17T12:00:00');
d.subtractHours(2); // 2025-09-17T10:00:00
subtractMinutes(n) - Subtracts minutes from the date
const d = new Date('2025-09-17T12:00:00');
d.subtractMinutes(30); // 2025-09-17T11:30:00
subtractMonths(n) - Subtracts months from the date
subtractSeconds(n) - Subtracts seconds from the date
const d = new Date('2025-09-17T12:00:00');
d.subtractSeconds(15); // 2025-09-17T11:59:45
subtractWeeks(n) - Subtracts weeks from the date
subtractYears(n) - Subtracts years from the date
toArray() - Converts date to array
new Date('2025-09-17T12:34:56.789Z').toArray();
// [2025, 9, 17, 12, 34, 56, 789]
toLongDate(locale?) - Returns long date format
new Date('2025-09-17').toLongDate(); // "17 September 2025"
new Date('2025-09-17').toLongDate('tr-TR'); // "17 Eylül 2025"
toMilliseconds() - Returns milliseconds
const d = new Date('1970-01-01T00:00:01.500Z');
d.toMilliseconds(); // 1500
toObject() - Converts date to object
new Date('2025-09-17T12:34:56.789Z').toObject();
// { year: 2025, month: 9, day: 17, hour: 12, minute: 34, second: 56, millisecond: 789 }
toShortDate(locale?) - Returns short date format
new Date('2025-09-17').toShortDate(); // "17/09/2025"
new Date('2025-09-17').toShortDate('en-GB'); // "17/09/2025"
toUnix() - Returns Unix timestamp
const d = new Date('1970-01-01T00:00:01Z');
d.toUnix(); // 1
weekNumber() - Returns week number
const d = new Date('2025-01-03');
d.weekNumber(); // 1
File utilities and operations.
sizeInKB() - Returns file size in KB
const file = new File(["Hello"], "hello.txt");
console.log(file.sizeInKB()); // ~0.005 KB
sizeInMB() - Returns file size in MB
const file = new File(["Hello"], "hello.txt");
console.log(file.sizeInMB()); // ~0.000005 MB
toBase64() - Converts file to base64
const base64 = await file.toBase64();
Function utilities and higher-order functions.
debounce(ms) - Debounces the function by given milliseconds
const log = () => console.log('Hi');
const debounced = log.debounce(300);
memoize() - Caches the results of the function for same arguments
const fib = (n: number): number => n <= 1 ? n : fib(n-1)+fib(n-2);
const fastFib = fib.memoize();
cancellable() - Makes function cancelable
const log = () => console.log('Hi');
const fn = log.cancellable();
fn();
fn.cancel();
compose(...fns) - Composes multiple functions
const double = (x: number) => x*2;
const increment = (x: number) => x+1;
const fn = Function.compose(double, increment);
fn(3); // double(increment(3)) => 8
curry() - Curries the function
const add = (a: number, b: number) => a + b;
const curried = add.curry();
curried(1)(2); // 3
delay(ms) - Delays function execution
const sayHi = () => console.log('Hi');
sayHi.delay(1000)(); // logs "Hi" after 1 second
once() - Ensures function runs only once
const init = () => console.log('Init');
const runOnce = init.once();
runOnce(); // "Init"
runOnce(); // does nothing
pipe(...fns) - Pipes functions together
const add = (a: number) => a + 1;
const double = (a: number) => a * 2;
const piped = add.pipe(double);
piped(2); // double(add(2)) = 6
safe() - Wraps function in try-catch
const risky = (x: number) => { if (x < 0) throw new Error(); return x * 2; };
const safeFn = risky.safe();
safeFn(5); // 10
safeFn(-3); // undefined
tap(fn) - Executes function and returns original value
const add = (x: number) => x + 1;
const wrapped = add.tap(result => console.log(result));
wrapped(2); // logs 3, returns 3
throttle(ms) - Throttles function execution
const log = () => console.log('Hi');
const throttled = log.throttle(500);
Global utility functions for type checking and validation.
isArray(value) - Checks if the given value is an array
isArray([1, 2, 3]); // true
isArray('hello'); // false
isArray({}); // false
isBoolean(value) - Checks if value is boolean
isBoolean(true); // true
isBoolean(false); // true
isBoolean(0); // false
isBoolean('true'); // false
isDate(value) - Checks if value is date
isDate(new Date()); // true
isDate('2023-01-01'); // false
isDate({}); // false
isEmpty(value) - Checks if value is empty
isEmpty(null); // true
isEmpty(undefined); // true
isEmpty(''); // true
isEmpty([]); // true
isEmpty({}); // true
isEmpty(0); // false
isEmpty('hello'); // false
isEmpty([1, 2, 3]); // false
isEmpty({ a: 1 }); // false
isFunction(value) - Checks if value is function
isFunction(function() {}); // true
isFunction(() => {}); // true
isFunction(class {}); // true
isFunction(123); // false
isFunction('hello'); // false
isNil(value) - Checks if value is null or undefined
isNil(null); // true
isNil(undefined); // true
isNil(0); // false
isNil(''); // false
isNumber(value) - Checks if value is number
isNumber(123); // true
isNumber('hello'); // false
isNumber(NaN); // false
isObject(value) - Checks if value is object
isObject({}); // true
isObject([]); // true
isObject(null); // false
isObject(123); // false
isPromise(value) - Checks if value is promise
isPromise(Promise.resolve()); // true
isPromise({ then: () => {}, catch: () => {} }); // true
isPromise(123); // false
isString(value) - Checks if value is string
isString('hello'); // true
isString(123); // false
isString({}); // false
isUndefined(value) - Checks if value is undefined
isUndefined(undefined); // true
isUndefined(null); // false
isUndefined(0); // false
JSON utilities and safe parsing.
safeParse(text) - Safely parses JSON string
JSON.safeParse('{"a":1}'); // { a: 1 }
JSON.safeParse('invalid'); // undefined
// Generic type example
interface User { id: number; name: string; }
const user = JSON.safeParse<User>('{"id":1,"name":"Alice"}');
if (user) {
console.log(user.id); // 1
}
safeStringify(value, space?) - Safely stringifies object to JSON
JSON.safeStringify({a:1}); // '{"a":1}'
JSON.safeStringify(() => {}); // undefined
Mathematical operations and utilities.
add(a, b) - Adds two numbers
Math.add(5, 3); // 8
average() - Calculates average
clamp(value, min, max) - Clamps value between min and max
Math.clamp(10, 0, 5); // 5
Math.clamp(-2, 0, 5); // 0
decrement() - Decrements number by 1
degToRad() - Converts degrees to radians
divide() - Divides two numbers
factorial(n) - Calculates factorial
Math.factorial(5); // 120
gcd(a, b) - Calculates greatest common divisor
Math.gcd(12, 18); // 6
geometricMean() - Calculates geometric mean
harmonicMean() - Calculates harmonic mean
increment() - Increments number by 1
isBetween() - Checks if number is between two values
isEven() - Checks if number is even
isFinite() - Checks if number is finite
isInfinity() - Checks if number is infinity
isInteger() - Checks if number is integer
isMultipleOf() - Checks if number is multiple of another
isNegative() - Checks if number is negative
isOdd() - Checks if number is odd
isPositive() - Checks if number is positive
isPrime() - Checks if number is prime
lcm() - Calculates least common multiple
lerp(a, b, t) - Linear interpolation
Math.lerp(0, 10, 0.5); // 5
maxArray() - Returns maximum from array
minArray() - Returns minimum from array
mod() - Modulo operation
multiply() - Multiplies two numbers
negate() - Negates number
normalize() - Normalizes value to 0-1 range
percentage() - Calculates percentage
product() - Calculates product of array
radToDeg() - Converts radians to degrees
randomBoolean() - Returns random boolean
randomChoice() - Returns random choice from array
randomFloat() - Returns random float
randomInt(min, max) - Returns random integer
Math.randomInt(1, 6); // 4
Math.randomInt(10, 20); // 15
randomSign() - Returns random sign
range() - Creates range of numbers
rootMeanSquare() - Calculates root mean square
roundTo() - Rounds to specified decimal places
scale() - Scales value to new range
signOrZero() - Returns sign or zero
subtract() - Subtracts two numbers
sum() - Calculates sum of array
toBinary() - Converts to binary
toFixed() - Formats number with fixed decimals
toHex() - Converts to hexadecimal
toInt() - Converts to integer
toRoman() - Converts to Roman numerals
zScore() - Calculates z-score
Number utilities and operations.
abs() - Returns the absolute value of the number
(-5).abs(); // 5
add() - Adds two numbers
average() - Calculates average
between() - Checks if number is between two values
cbrt() - Calculates cube root
ceil() - Rounds up to nearest integer
(3.01).ceil(); // 4
clamp() - Clamps value between min and max
cube() - Calculates cube
(3).cube(); // 27
decrement() - Decrements by 1
divide() - Divides two numbers
divisors() - Returns divisors
equals(other, tolerance?) - Checks equality
(5.01).equals(5, 0.1); // true
exp() - Calculates exponential
(1).exp(); // Math.E
factorial() - Calculates factorial
floor() - Rounds down to nearest integer
(3.99).floor(); // 3
gcd() - Calculates greatest common divisor
increment() - Increments by 1
inRange(min, max, inclusive?) - Checks if in range
(5).inRange(1, 10); // true
isBetween() - Checks if between two values
isEven() - Checks if even
(4).isEven(); // true
(5).isEven(); // false
isFibonacci() - Checks if Fibonacci number
(8).isFibonacci(); // true
isFinite() - Checks if finite
isFloat() - Checks if float
(5.5).isFloat(); // true
(5).isFloat(); // false
isInfinity() - Checks if infinity
(Infinity).isInfinity(); // true
(-Infinity).isInfinity(); // true
(5).isInfinity(); // false
isInteger() - Checks if integer
(5).isInteger(); // true
(5.5).isInteger(); // false
isMultipleOf(other) - Checks if multiple of
(12).isMultipleOf(3); // true
(12).isMultipleOf(5); // false
isNegative() - Checks if negative
(-5).isNegative(); // true
(3).isNegative(); // false
isOdd() - Checks if odd
isPerfect() - Checks if perfect number
(6).isPerfect(); // true
isPerfectSquare() - Checks if perfect square
(16).isPerfectSquare(); // true
(20).isPerfectSquare(); // false
isPositive() - Checks if positive
(5).isPositive(); // true
(-3).isPositive(); // false
isPrime() - Checks if prime
(7).isPrime(); // true
(10).isPrime(); // false
isZero() - Checks if zero
(0).isZero(); // true
(5).isZero(); // false
lcm() - Calculates least common multiple
log(base?) - Calculates logarithm
(10).log(); // Math.log(10)
(8).log(2); // 3
median(...others) - Calculates median
(5).median(10, 15); // 10
mod() - Modulo operation
multiply() - Multiplies two numbers
negate() - Negates number
nthRoot(n) - Calculates nth root
(27).nthRoot(3); // 3
padEnd(length, char?) - Pads string representation
(5).padEnd(3); // "5--"
padStart() - Pads string representation
pow() - Calculates power
round(decimals?) - Rounds to nearest integer
(3.14159).round(2); // 3.14
(3.14159).round(); // 3
roundTo() - Rounds to specified decimals
sign() - Returns sign
sqrt() - Calculates square root
(9).sqrt(); // 3
square() - Calculates square
subtract() - Subtracts two numbers
surround() - Surrounds with characters
times() - Repeats function n times
toBinary() - Converts to binary
toBinaryFileSize() - Converts to binary file size
toCurrency() - Converts to currency format
toDate() - Converts to date
toDays() - Converts to days
toDaysFromHours() - Converts hours to days
toDaysFromMinutes() - Converts minutes to days
toDaysFromMonths() - Converts months to days
toDaysFromSeconds() - Converts seconds to days
toDaysFromWeeks() - Converts weeks to days
toDaysFromYears() - Converts years to days
toDegree() - Converts to degrees
toDuration() - Converts to duration string
toFileSize() - Converts to file size
toHex() - Converts to hexadecimal
toHours() - Converts to hours
toLongDuration() - Converts to long duration
toMilliseconds() - Converts to milliseconds
toMinutes() - Converts to minutes
toMonths() - Converts to months
toOctal() - Converts to octal
toPadded() - Pads number
toPercent() - Converts to percentage
toPercentString() - Converts to percentage string
toRadian() - Converts to radians
toRoman() - Converts to Roman numerals
(9).toRoman(); // "IX"
toSeconds() - Converts to seconds
toSeparated() - Adds separators
toTime() - Converts to time string
toWeeks() - Converts to weeks
toWords() - Converts to words
toYears() - Converts to years
variance() - Calculates variance
Object manipulation and utility functions.
clone(obj) - Creates a shallow clone of an object
Object.clone({ a: 1, b: 2 }); // { a: 1, b: 2 }
countKeys(obj) - Counts object keys
Object.countKeys({ a:1, b:2 }); // 2
countValues(obj) - Counts object values
Object.countValues({ a:1, b:2 }); // 2
deepClone(obj) - Creates deep clone
Object.deepClone({ a: { b: 1 } }); // { a: { b:1 } } (new nested object)
defaults() - Sets default values
every() - Checks if all properties satisfy condition
filter(obj, fn) - Filters object properties
Object.filter({ a:1, b:2, c:3 }, (v) => v > 1); // { b:2, c:3 }
filterKeys(obj, fn) - Filters object keys
Object.filterKeys({ a:1, b:2, c:3 }, k => k !== 'b'); // { a:1, c:3 }
filterValues(obj, fn) - Filters object values
Object.filterValues({ a:1, b:2, c:3 }, v => v > 1); // { b:2, c:3 }
findKey(obj, fn) - Finds key by value
Object.findKey({ a:1, b:2 }, v => v === 2); // 'b'
findValue(obj, fn) - Finds value by key
Object.findValue({ a:1, b:2 }, v => v > 1); // 2
fromFlat(obj, separator?) - Creates object from flat structure
Object.fromFlat({ 'a.b': 1 }); // { a: { b: 1 } }
get() - Gets nested property
hasKey(obj, key) - Checks if has key
Object.hasKey({ a: 1 }, 'a'); // true
Object.hasKey({ a: 1 }, 'b'); // false
hasKeys(obj, keys) - Checks if has keys
Object.hasKeys({ a: 1, b: 2 }, ['a','b']); // true
Object.hasKeys({ a: 1 }, ['a','b']); // false
hasPath() - Checks if has path
hasValue() - Checks if has value
invert() - Inverts key-value pairs
isEmpty() - Checks if object is empty
isEqual() - Checks deep equality
isPlainObject() - Checks if plain object
isShallowEqual() - Checks shallow equality
mapKeys() - Maps object keys
mapValues() - Maps object values
merge(target, source) - Deep merges two objects
Object.merge({ a: { x: 1 } }, { a: { y: 2 } }); // { a: { x:1, y:2 } }
omit() - Omits specified keys
pick() - Picks specified keys
reject() - Rejects properties by condition
setIfUndefined() - Sets value if undefined
size() - Returns object size
some() - Checks if any property satisfies condition
tap() - Executes function and returns object
toFlat() - Flattens object
toPairs() - Converts to key-value pairs
unset() - Removes property
update() - Updates property
Promise utilities and helpers.
delay(ms) - Delays promise resolution
Promise.resolve(42).delay(1000).then(console.log); // logs 42 after 1s
retry(times, delayMs?) - Retries promise on failure
tap(fn) - Executes function and returns promise
Promise.resolve(42)
.tap(value => console.log(value)) // logs 42
.then(value => console.log(value)); // 42
timeout(ms, error?) - Adds timeout to promise
Promise.resolve(42).timeout(1000).then(console.log);
String manipulation and utility functions.
capitalize() - Capitalizes only the first letter of the string
'hello'.capitalize(); // 'Hello'
chunk(n) - Splits string into chunks
'abcdef'.chunk(2); // ['ab','cd','ef']
contains(substr) - Checks if string contains substring
'hello world'.contains('world'); // true
count(substr) - Counts occurrences
'ababab'.count('ab'); // 3
drop(n) - Removes first n characters
'hello'.drop(2); // 'llo'
dropLast(n) - Removes last n characters
'hello'.dropLast(2); // 'hel'
endsWithIgnoreCase(substr) - Checks if ends with (case insensitive)
'Hello World'.endsWithIgnoreCase('WORLD'); // true
first(n?) - Returns first character
'hello'.first(2); // 'he'
'hello'.first(); // 'h'
'hello'.first(0); // ''
'hello'.first(10); // 'hello'
firstWord() - Returns first word
'Hello world!'.firstWord(); // 'Hello'
''.firstWord(); // ''
includesIgnoreCase(substr) - Checks if includes (case insensitive)
'Hello World'.includesIgnoreCase('hello'); // true
indexAll(substr) - Returns all indices of substring
'ababab'.indexAll('ab'); // [0,2,4]
isAlpha() - Checks if alphabetic
isAlphaNumeric() - Checks if alphanumeric
isAnagramOf() - Checks if anagram
isBase64() - Checks if base64
isBinary() - Checks if binary
isBlank() - Checks if blank
isCreditCard() - Checks if credit card number
isDate() - Checks if date string
isDomain() - Checks if domain
isEmail() - Checks if email
'user@example.com'.isEmail(); // true
'user@com'.isEmail(); // false
isEmoji() - Checks if emoji
isEmpty() - Checks if empty
isFloat() - Checks if float string
isHex() - Checks if hexadecimal
isInteger() - Checks if integer string
isIp() - Checks if IP address
isIsoDate() - Checks if ISO date
isJSON() - Checks if JSON string
isLowerCase() - Checks if lowercase
isNumeric() - Checks if numeric
isOctal() - Checks if octal
isPalindrome() - Checks if palindrome
isPhone() - Checks if phone number
isTime() - Checks if time string
isUpperCase() - Checks if uppercase
isURL() - Checks if URL
isUUID() - Checks if UUID
isWhitespace() - Checks if whitespace
last() - Returns last character
lastWord() - Returns last word
lengthStats() - Returns length statistics
normalizeSpaces() - Normalizes spaces
padBoth() - Pads both sides
remove() - Removes characters
reverse() - Reverses string
'hello'.reverse(); // 'olleh'
splitLines() - Splits into lines
startsWithIgnoreCase() - Checks if starts with (case insensitive)
stripNonAlpha() - Strips non-alphabetic characters
stripNumbers() - Strips numbers
stripPunctuation() - Strips punctuation
stripSymbols() - Strips symbols
stripWhitespace() - Strips whitespace
surround() - Surrounds with characters
take() - Takes first n characters
takeLast() - Takes last n characters
tap() - Executes function and returns string
toArray() - Converts to character array
toAscii() - Converts to ASCII
toBinary() - Converts to binary
toBoolean() - Converts to boolean
toCamelCase() - Converts to camelCase
'foo_bar'.toCamelCase(); // 'fooBar'
'hello-world'.toCamelCase(); // 'helloWorld'
toCharCodes() - Converts to character codes
toDate() - Converts to date
toFloat() - Converts to float
toHex() - Converts to hexadecimal
toInt() - Converts to integer
toKebabCase() - Converts to kebab-case
toMorse() - Converts to Morse code
toNumber() - Converts to number
toPascalCase() - Converts to PascalCase
toSlug() - Converts to slug
toSnakeCase() - Converts to snake_case
toSwapCase() - Converts to swap case
toTitleCase() - Converts to Title Case
toUnicode() - Converts to Unicode
truncate() - Truncates string
words() - Splits into words
MIT
FAQs
Extend Core is a TypeScript library that provides a collection of utility functions to extend and enhance the functionality of JavaScript's core objects, such as Array, String, Object, Date, Number, JSON, File, Buffer, Function, and Promise. It offers a w
The npm package extend-core receives a total of 1 weekly downloads. As such, extend-core popularity was classified as not popular.
We found that extend-core demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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