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Apply a callback function to elements in an input array and assign results to elements in a new output array.
import map from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-map@esm/index.mjs';You can also import the following named exports from the package:
import { assign } from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-map@esm/index.mjs';Applies a callback function to elements in an input array and assigns results to elements in a new output array.
import naryFunction from 'https://cdn.jsdelivr.net/gh/stdlib-js/utils-nary-function@esm/index.mjs';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@esm/index.mjs';
var x = [ -1.0, -2.0, -3.0, -4.0 ];
var y = map( x, naryFunction( abs, 1 ) );
// returns [ 1.0, 2.0, 3.0, 4.0 ]The function accepts the following arguments:
- x: input array.
- fcn: callback function.
- thisArg: callback execution context (optional).
To set the callback function's execution context, provide a thisArg.
function count( x ) {
this.count += 1;
return x;
}
var x = [ 1.0, 2.0, 3.0, 4.0 ];
var ctx = {
'count': 0
};
var y = map( x, count, ctx );
// returns [ 1.0, 2.0, 3.0, 4.0 ]
var v = ctx.count;
// returns 4The callback function is provided the following arguments:
- value: current array element.
- index: current element index.
- arr: input array.
Applies a callback function to elements in an input array and assigns results to elements in an output array.
import naryFunction from 'https://cdn.jsdelivr.net/gh/stdlib-js/utils-nary-function@esm/index.mjs';
import zeros from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-zeros@esm/index.mjs';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@esm/index.mjs';
var x = [ -1.0, -2.0, -3.0, -4.0 ];
var y = zeros( x.length );
var out = map.assign( x, y, 1, 0, naryFunction( abs, 1 ) );
// returns [ 1.0, 2.0, 3.0, 4.0 ]
var bool = ( out === y );
// returns trueThe function accepts the following arguments:
- x: input array.
- y: output array.
- stride: stride length for output array.
- offset: starting index for output array.
- fcn: callback function.
- thisArg: callback execution context (optional).
-
If provided an array-like object having a
mapmethod, the function defers execution to that method and assumes that the method API has the following signature:x.map( fcn, thisArg ) -
The function supports array-like objects having getter and setter accessors for array element access (e.g.,
@stdlib/array-base/accessor).
<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">
import discreteUniform from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-array-discrete-uniform@esm/index.mjs';
import naryFunction from 'https://cdn.jsdelivr.net/gh/stdlib-js/utils-nary-function@esm/index.mjs';
import abs from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-abs@esm/index.mjs';
import map from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-map@esm/index.mjs';
var x = discreteUniform( 10, -10, 10, {
'dtype': 'float64'
});
var y = map( x, naryFunction( abs, 1 ) );
console.log( y );
</script>
</body>
</html>This package is part of stdlib, a standard library 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 © 2016-2026. The Stdlib Authors.