is-zero-or-positive-integer

is-zero-or-positive-integer

Node.js helper function: test variables for being a zero or a positive integer.

Installation

npm install is-zero-or-positive-integer

Usage

const isZeroOrPositiveInteger = require('is-zero-or-positive-integer');

/*
    If you only want to check for safe integers:
    const isZeroOrPositiveInteger = require('is-zero-or-positive-integer').onlyTrueIfSafe;
    See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number/MAX_SAFE_INTEGER for further reference.
*/

// numbers
console.log( isZeroOrPositiveInteger(0) ); //true
console.log( isZeroOrPositiveInteger(1) ); //true
console.log( isZeroOrPositiveInteger(-1) ); //false
console.log( isZeroOrPositiveInteger(2147483647) ); //true
console.log( isZeroOrPositiveInteger(-2147483648) ); //false
console.log( isZeroOrPositiveInteger(Number.MAX_SAFE_INTEGER) ); //true
console.log( isZeroOrPositiveInteger(Number.MIN_SAFE_INTEGER) ); //false
console.log( isZeroOrPositiveInteger(1e+23) ); //true
console.log( isZeroOrPositiveInteger(-1e+23) ); //false

// strings
console.log( isZeroOrPositiveInteger('0') ); //true
console.log( isZeroOrPositiveInteger('1') ); //true
console.log( isZeroOrPositiveInteger('01') ); //true
console.log( isZeroOrPositiveInteger('-1') ); //false
console.log( isZeroOrPositiveInteger('2147483647') ); //true
console.log( isZeroOrPositiveInteger('-2147483648') ); //false
console.log( isZeroOrPositiveInteger('9007199254740991') ); //true
console.log( isZeroOrPositiveInteger('-9007199254740991') ); //false
console.log( isZeroOrPositiveInteger('1e+23') ); //true
console.log( isZeroOrPositiveInteger('-1e+23') ); //false
console.log( isZeroOrPositiveInteger('string') ); //false

// other
console.log( isZeroOrPositiveInteger({}) ); //false
console.log( isZeroOrPositiveInteger([]) ); //false
console.log( isZeroOrPositiveInteger(Symbol()) ); //false
console.log( isZeroOrPositiveInteger(new Date()) ); //false
console.log( isZeroOrPositiveInteger(new Date().getTime()) ); //true
console.log( isZeroOrPositiveInteger(function() { return; }) ); //false

/* visual representation mode (vrm): 
   if set true then consider values with 
   - scientific notation (1e+23)
   - leading zeroes ('0123')
   as being no integer!
*/
console.log( isZeroOrPositiveInteger(1e+23, true) ); //false
console.log( isZeroOrPositiveInteger('01', true) ); //false