@stdlib/array-uint8c
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Typed array constructor which returns a typed array representing an array of 8-bit unsigned integers in the platform byte order clamped to 0-255.
npm install @stdlib/array-uint8c
var Uint8ClampedArray = require( '@stdlib/array-uint8c' );
A typed array constructor which returns a typed array representing an array of 8-bit unsigned integers in the platform byte order clamped to 0-255.
var arr = new Uint8ClampedArray();
// returns <Uint8ClampedArray>
Returns a typed array having a specified length.
var arr = new Uint8ClampedArray( 5 );
// returns <Uint8ClampedArray>[ 0, 0, 0, 0, 0 ]
Creates a typed array from another typed array.
var Float32Array = require( '@stdlib/array-float32' );
var arr1 = new Float32Array( [ 5.0, 5.0, 5.0 ] );
var arr2 = new Uint8ClampedArray( arr1 );
// returns <Uint8ClampedArray>[ 5, 5, 5 ]
Creates a typed array from an array-like object or iterable.
var arr = new Uint8ClampedArray( [ 5.0, 5.0, 5.0 ] );
// returns <Uint8ClampedArray>[ 5, 5, 5 ]
Returns a typed array view of an ArrayBuffer.
var ArrayBuffer = require( '@stdlib/array-buffer' );
var buf = new ArrayBuffer( 4 );
var arr = new Uint8ClampedArray( buf, 0, 4 );
// returns <Uint8ClampedArray>[ 0, 0, 0, 0 ]
Number of bytes per view element.
var nbytes = Uint8ClampedArray.BYTES_PER_ELEMENT;
// returns 1
Typed array constructor name.
var str = Uint8ClampedArray.name;
// returns 'Uint8ClampedArray'
Read-only property which returns the ArrayBuffer referenced by the typed array.
var arr = new Uint8ClampedArray( 5 );
var buf = arr.buffer;
// returns <ArrayBuffer>
Read-only property which returns the length (in bytes) of the typed array.
var arr = new Uint8ClampedArray( 5 );
var byteLength = arr.byteLength;
// returns 5
Read-only property which returns the offset (in bytes) of the typed array from the start of its ArrayBuffer.
var arr = new Uint8ClampedArray( 5 );
var byteOffset = arr.byteOffset;
// returns 0
Number of bytes per view element.
var arr = new Uint8ClampedArray( 5 );
var nbytes = arr.BYTES_PER_ELEMENT;
// returns 1
Read-only property which returns the number of view elements.
var arr = new Uint8ClampedArray( 5 );
var len = arr.length;
// returns 5
Creates a new typed array from an array-like object or an iterable.
var arr = Uint8ClampedArray.from( [ 1, 2 ] );
// returns <Uint8ClampedArray>[ 1, 2 ]
To invoke a function for each src value, provide a callback function.
function mapFcn( v ) {
return v * 2;
}
var arr = Uint8ClampedArray.from( [ 1, 2 ], mapFcn );
// returns <Uint8ClampedArray>[ 2, 4 ]
A callback function is provided two arguments:
value: source valueindex: source indexTo set the callback execution context, provide a thisArg.
function mapFcn( v ) {
this.count += 1;
return v * 2;
}
var ctx = {
'count': 0
};
var arr = Uint8ClampedArray.from( [ 1, 2 ], mapFcn, ctx );
// returns <Uint8ClampedArray>[ 2, 4 ]
var n = ctx.count;
// returns 2
Creates a new typed array from a variable number of arguments.
var arr = Uint8ClampedArray.of( 1, 2 );
// returns <Uint8ClampedArray>[ 1, 2 ]
Copies a sequence of elements within an array starting at start and ending at end (non-inclusive) to the position starting at target.
var arr = new Uint8ClampedArray( [ 1, 2, 3, 4, 5 ] );
// Copy the last two elements to the first two elements:
arr.copyWithin( 0, 3 );
var v = arr[ 0 ];
// returns 4
v = arr[ 1 ];
// returns 5
By default, end equals the number of array elements (i.e., one more than the last array index). To limit the sequence length, provide an end argument.
var arr = new Uint8ClampedArray( [ 1, 2, 3, 4, 5 ] );
// Copy the first two elements to the last two elements:
arr.copyWithin( 3, 0, 2 );
var v = arr[ 3 ];
// returns 1
v = arr[ 4 ];
// returns 2
When a target, start, and/or end index is negative, the respective index is determined relative to the last array element. The following example achieves the same behavior as the previous example:
var arr = new Uint8ClampedArray( [ 1, 2, 3, 4, 5 ] );
// Copy the first two elements to the last two elements:
arr.copyWithin( -2, -5, -3 );
var v = arr[ 3 ];
// returns 1
v = arr[ 4 ];
// returns 2
Returns an iterator for iterating over array key-value pairs.
var arr = new Uint8ClampedArray( [ 1, 2 ] );
// Create an iterator:
var it = arr.entries();
// Iterate over key-value pairs...
var v = it.next().value;
// returns [ 0, 1 ]
v = it.next().value;
// returns [ 1, 2 ]
var bool = it.next().done;
// returns true
Tests whether all array elements pass a test implemented by a predicate function.
function predicate( v ) {
return ( v <= 1 );
}
var arr = new Uint8ClampedArray( [ 1, 2 ] );
var bool = arr.every( predicate );
// returns false
A predicate function is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return ( v >= 1 );
}
var ctx = {
'count': 0
};
var arr = new Uint8ClampedArray( [ 1, 2 ] );
var bool = arr.every( predicate, ctx );
// returns true
var n = ctx.count;
// returns 2
Fills an array from a start index to an end index (non-inclusive) with a provided value.
var arr = new Uint8ClampedArray( 2 );
// Set all array elements to the same value:
arr.fill( 2 );
var v = arr[ 0 ];
// returns 2
v = arr[ 1 ];
// returns 2
// Set all array elements starting from the first index to the same value:
arr.fill( 3, 1 );
v = arr[ 0 ];
// returns 2
v = arr[ 1 ];
// returns 3
// Set all array elements, except the last element, to the same value:
arr.fill( 4, 0, arr.length-1 );
v = arr[ 0 ];
// returns 4
v = arr[ 1 ];
// returns 3
When a start and/or end index is negative, the respective index is determined relative to the last array element.
var arr = new Uint8ClampedArray( 2 );
// Set all array elements, except the last element, to the same value:
arr.fill( 2, -arr.length, -1 );
var v = arr[ 0 ];
// returns 2
v = arr[ 1 ];
// returns 0
Creates a new array (of the same data type as the host array) which includes those elements for which a predicate function returns a truthy value.
function predicate( v ) {
return ( v >= 2 );
}
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.filter( predicate );
// returns <Uint8ClampedArray>[ 2, 3 ]
If a predicate function does not return a truthy value for any array element, the method returns an empty array.
function predicate( v ) {
return ( v >= 10 );
}
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.filter( predicate );
// returns <Uint8ClampedArray>[]
A predicate function is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return ( v >= 2 );
}
var ctx = {
'count': 0
};
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.filter( predicate, ctx );
var n = ctx.count;
// returns 3
Returns the first array element for which a provided predicate function returns a truthy value.
function predicate( v ) {
return ( v > 2 );
}
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var v = arr.find( predicate );
// returns 3
If a predicate function does not return a truthy value for any array element, the method returns undefined.
function predicate( v ) {
return ( v < 1 );
}
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var v = arr.find( predicate );
// returns undefined
A predicate function is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return ( v > 2 );
}
var ctx = {
'count': 0
};
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var v = arr.find( predicate, ctx );
// returns 3
var n = ctx.count;
// returns 3
Returns the index of the first array element for which a provided predicate function returns a truthy value.
function predicate( v ) {
return ( v >= 3 );
}
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.findIndex( predicate );
// returns 2
If a predicate function does not return a truthy value for any array element, the method returns -1.
function predicate( v ) {
return ( v < 1 );
}
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.findIndex( predicate );
// returns -1
A predicate function is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return ( v >= 3 );
}
var ctx = {
'count': 0
};
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.findIndex( predicate, ctx );
// returns 2
var n = ctx.count;
// returns 3
Invokes a callback for each array element.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var str = '';
function fcn( v, i ) {
str += i + ':' + v;
if ( i < arr.length-1 ) {
str += ' ';
}
}
arr.forEach( fcn );
console.log( str );
// => '0:1 1:2 2:3'
The callback is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function fcn() {
this.count += 1;
}
var ctx = {
'count': 0
};
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
arr.forEach( fcn, ctx );
var n = ctx.count;
// returns 3
Returns a boolean indicating whether an array includes a search element.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var bool = arr.includes( 3 );
// returns true
bool = arr.includes( 0 );
// returns false
By default, the method searches the entire array (fromIndex = 0). To begin searching from a specific array index, provide a fromIndex.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var bool = arr.includes( 1, 1 );
// returns false
When a fromIndex is negative, the starting index is resolved relative to the last array element.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var bool = arr.includes( 1, -2 );
// returns false
Returns the index of the first array element strictly equal to a search element.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.indexOf( 3 );
// returns 2
idx = arr.indexOf( 0 );
// returns -1
By default, the method searches the entire array (fromIndex = 0). To begin searching from a specific array index, provide a fromIndex.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.indexOf( 1, 1 );
// returns -1
When a fromIndex is negative, the starting index is resolved relative to the last array element.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var idx = arr.indexOf( 1, -2 );
// returns -1
Serializes an array by joining all array elements as a string.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var str = arr.join();
// returns '1,2,3'
By default, the method delineates array elements using a comma ,. To specify a custom separator, provide a separator string.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var str = arr.join( '|' );
// returns '1|2|3'
Returns an iterator for iterating over array keys.
var arr = new Uint8ClampedArray( [ 1, 2 ] );
// Create an iterator:
var it = arr.keys();
// Iterate over keys...
var v = it.next().value;
// returns 0
v = it.next().value;
// returns 1
var bool = it.next().done;
// returns true
Returns the index of the last array element strictly equal to a search element, iterating from right to left.
var arr = new Uint8ClampedArray( [ 1, 0, 2, 0, 1 ] );
var idx = arr.lastIndexOf( 0 );
// returns 3
idx = arr.lastIndexOf( 3 );
// returns -1
By default, the method searches the entire array (fromIndex = -1). To begin searching from a specific array index, provide a fromIndex.
var arr = new Uint8ClampedArray( [ 1, 0, 2, 0, 1 ] );
var idx = arr.lastIndexOf( 0, 2 );
// returns 1
When a fromIndex is negative, the starting index is resolved relative to the last array element.
var arr = new Uint8ClampedArray( [ 1, 0, 2, 0, 1 ] );
var idx = arr.lastIndexOf( 0, -3 );
// returns 1
Maps each array element to an element in a new array having the same data type as the host array.
function fcn( v ) {
return v * 2;
}
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.map( fcn );
// returns <Uint8ClampedArray>[ 2, 4, 6 ]
A callback is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function fcn( v ) {
this.count += 1;
return v * 2;
}
var ctx = {
'count': 0
};
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.map( fcn, ctx );
var n = ctx.count;
// returns 3
Applies a function against an accumulator and each element in an array and returns the accumulated result.
function fcn( acc, v ) {
return acc + ( v*v );
}
var arr = new Uint8ClampedArray( [ 2, 1, 3 ] );
var v = arr.reduce( fcn );
// returns 12
If not provided an initial value, the method invokes a provided function with the first array element as the first argument and the second array element as the second argument.
If provided an initial value, the method invokes a provided function with the initial value as the first argument and the first array element as the second argument.
function fcn( acc, v ) {
return acc + ( v*v );
}
var arr = new Uint8ClampedArray( [ 2, 1, 3 ] );
var v = arr.reduce( fcn, 0 );
// returns 14
A callback is provided four arguments:
acc: accumulated resultvalue: array elementindex: array indexarr: array on which the method is invokedApplies a function against an accumulator and each element in an array and returns the accumulated result, iterating from right to left.
function fcn( acc, v ) {
return acc + ( v*v );
}
var arr = new Uint8ClampedArray( [ 2, 1, 3 ] );
var v = arr.reduceRight( fcn );
// returns 8
If not provided an initial value, the method invokes a provided function with the last array element as the first argument and the second-to-last array element as the second argument.
If provided an initial value, the method invokes a provided function with the initial value as the first argument and the last array element as the second argument.
function fcn( acc, v ) {
return acc + ( v*v );
}
var arr = new Uint8ClampedArray( [ 2, 1, 3 ] );
var v = arr.reduce( fcn, 0 );
// returns 14
A callback is provided four arguments:
acc: accumulated resultvalue: array elementindex: array indexarr: array on which the method is invokedReverses an array in-place (thus mutating the array on which the method is invoked).
var arr = new Uint8ClampedArray( [ 2, 0, 3 ] );
// Reverse the array:
arr.reverse();
var v = arr[ 0 ];
// returns 3
v = arr[ 1 ];
// returns 0
v = arr[ 2 ];
// returns 2
Sets array elements.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
// returns <Uint8ClampedArray>[ 1, 2, 3 ]
// Set the first two array elements:
arr.set( [ 4, 5 ] );
var v = arr[ 0 ];
// returns 4
v = arr[ 1 ];
// returns 5
By default, the method starts writing values at the first array index. To specify an alternative index, provide an index offset.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
// returns <Uint8ClampedArray>[ 1, 2, 3 ]
// Set the last two array elements:
arr.set( [ 4, 5 ], 1 );
var v = arr[ 1 ];
// returns 4
v = arr[ 2 ];
// returns 5
Copies array elements to a new array with the same underlying data type as the host array.
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.slice();
var bool = ( arr1 === arr2 );
// returns false
bool = ( arr1.buffer === arr2.buffer );
// returns false
var v = arr2[ 0 ];
// returns 1
v = arr2[ 1 ];
// returns 2
v = arr2[ 2 ];
// returns 3
By default, the method copies elements beginning with the first array element. To specify an alternative array index at which to begin copying, provide a begin index (inclusive).
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.slice( 1 );
var len = arr2.length;
// returns 2
var v = arr2[ 0 ];
// returns 2
v = arr2[ 1 ];
// returns 3
By default, the method copies all array elements after begin. To specify an alternative array index at which to end copying, provide an end index (exclusive).
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.slice( 0, 2 );
var len = arr2.length;
// returns 2
var v = arr2[ 0 ];
// returns 1
v = arr2[ 1 ];
// returns 2
When a begin and/or end index is negative, the respective index is determined relative to the last array element.
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.slice( -arr1.length, -1 );
var len = arr2.length;
// returns 2
var v = arr2[ 0 ];
// returns 1
v = arr2[ 1 ];
// returns 2
Tests whether at least one array element passes a test implemented by a predicate function.
function predicate( v ) {
return ( v >= 2 );
}
var arr = new Uint8ClampedArray( [ 1, 2 ] );
var bool = arr.some( predicate );
// returns true
A predicate function is provided three arguments:
value: array elementindex: array indexarr: array on which the method is invokedTo set the callback execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return ( v >= 2 );
}
var ctx = {
'count': 0
};
var arr = new Uint8ClampedArray( [ 1, 1 ] );
var bool = arr.some( predicate, ctx );
// returns false
var n = ctx.count;
// returns 2
Sorts an array in-place (thus mutating the array on which the method is invoked).
var arr = new Uint8ClampedArray( [ 2, 3, 0 ] );
// Sort the array (in ascending order):
arr.sort();
var v = arr[ 0 ];
// returns 0
v = arr[ 1 ];
// returns 2
v = arr[ 2 ];
// returns 3
By default, the method sorts array elements in ascending order. To impose a custom order, provide a compareFunction.
function descending( a, b ) {
return b - a;
}
var arr = new Uint8ClampedArray( [ 2, 3, 0 ] );
// Sort the array (in descending order):
arr.sort( descending );
var v = arr[ 0 ];
// returns 3
v = arr[ 1 ];
// returns 2
v = arr[ 2 ];
// returns 0
The comparison function is provided two array elements, a and b, per invocation, and its return value determines the sort order as follows:
a to an index lower than b (i.e., a should come before b).a to an index higher than b (i.e., b should come before a).a and b should remain unchanged.Creates a new typed array view over the same underlying ArrayBuffer and with the same underlying data type as the host array.
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.subarray();
// returns <Uint8ClampedArray>[ 1, 2, 3 ]
var bool = ( arr1.buffer === arr2.buffer );
// returns true
By default, the method creates a typed array view beginning with the first array element. To specify an alternative array index at which to begin, provide a begin index (inclusive).
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.subarray( 1 );
// returns <Uint8ClampedArray>[ 2, 3 ]
var bool = ( arr1.buffer === arr2.buffer );
// returns true
By default, the method creates a typed array view which includes all array elements after begin. To limit the number of array elements after begin, provide an end index (exclusive).
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.subarray( 0, 2 );
// returns <Uint8ClampedArray>[ 1, 2 ]
var bool = ( arr1.buffer === arr2.buffer );
// returns true
When a begin and/or end index is negative, the respective index is determined relative to the last array element.
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.subarray( -arr1.length, -1 );
// returns <Uint8ClampedArray>[ 1, 2 ]
var bool = ( arr1.buffer === arr2.buffer );
// returns true
If the method is unable to resolve indices to a non-empty array subsequence, the method returns an empty typed array.
var arr1 = new Uint8ClampedArray( [ 1, 2, 3 ] );
var arr2 = arr1.subarray( 10, -1 );
// returns <Uint8ClampedArray>[]
Serializes an array as a locale-specific string.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var str = arr.toLocaleString();
// returns '1,2,3'
Serializes an array as a string.
var arr = new Uint8ClampedArray( [ 1, 2, 3 ] );
var str = arr.toString();
// returns '1,2,3'
Returns an iterator for iterating over array elements.
var arr = new Uint8ClampedArray( [ 1, 2 ] );
// Create an iterator:
var it = arr.values();
// Iterate over array elements...
var v = it.next().value;
// returns 1
v = it.next().value;
// returns 2
var bool = it.next().done;
// returns true
var randu = require( '@stdlib/random-base-randu' );
var round = require( '@stdlib/math-base-special-round' );
var ctor = require( '@stdlib/array-uint8c' );
var arr;
var i;
arr = new ctor( 10 );
for ( i = 0; i < arr.length; i++ ) {
arr[ i ] = round( randu()*100.0 );
}
console.log( arr );
@stdlib/array-buffer: ArrayBuffer.@stdlib/array-float32: Float32Array.@stdlib/array-float64: Float64Array.@stdlib/array-int16: Int16Array.@stdlib/array-int32: Int32Array.@stdlib/array-int8: Int8Array.@stdlib/array-uint16: Uint16Array.@stdlib/array-uint32: Uint32Array.@stdlib/array-uint8: Uint8Array.This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.
For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.
See LICENSE.
Copyright © 2016-2024. The Stdlib Authors.
0.2.2 (2024-07-27)
<section class="commits">A total of 1 person contributed to this release. Thank you to this contributor:
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