README
pop
Remove and return the last element of a collection.
Installation
npm install @stdlib/utils-pop
Usage
var pop = require( '@stdlib/utils-pop' );
pop( collection )
Removes and returns the last element of a collection. A collection may be either an Array, Typed Array, or an array-like Object (i.e., an Object having a valid writable length property).
var arr = [ 1.0, 2.0, 3.0, 4.0, 5.0 ];
var out = pop( arr );
// returns [ [ 1.0, 2.0, 3.0, 4.0 ], 5.0 ]
var bool = ( out[ 0 ] === arr );
// returns true
var lastValue = out[ 1 ];
// returns 5.0
In contrast to Array.prototype.pop which returns only the removed element, the function also returns the shortened collection. For typed arrays having a length greater than 0, the returned collection is a new typed array view.
var Float64Array= require( '@stdlib/array-float64' );
var arr = new Float64Array( 2 );
arr[ 0 ] = 1.0;
arr[ 1 ] = 2.0;
var out = pop( arr );
// returns [ <Float64Array>[ 1.0 ], 2.0 ]
var bool = ( out[ 0 ] === arr );
// returns false
bool = ( out[ 0 ].buffer === arr.buffer );
// returns true
var lastValue = out[ 1 ];
// returns 2.0
Notes
- When provided a typed array, the function does not change the underlying
ArrayBuffer. The function returns a new typed array view whose length is one less than the input typed array length. Accordingly, the function does not reduce the memory footprint of an input typed array.
Examples
var Float64Array= require( '@stdlib/array-float64' );
var pop = require( '@stdlib/utils-pop' );
var arr;
var out;
var i;
arr = new Float64Array( 100 );
for ( i = 0; i < 100; i++ ) {
out = pop( arr );
arr = out[ 0 ];
console.log( 'Length: %d', arr.length );
}
console.log( arr );
Notice
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.
Community
License
See LICENSE.
Copyright
Copyright © 2016-2022. The Stdlib Authors.