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About stdlib...

We believe in a future in which the web is a preferred environment for numerical computation. To help realize this future, we've built stdlib. stdlib is a standard library, with an emphasis on numerical and scientific computation, written in JavaScript (and C) for execution in browsers and in Node.js.

The library is fully decomposable, being architected in such a way that you can swap out and mix and match APIs and functionality to cater to your exact preferences and use cases.

When you use stdlib, you can be absolutely certain that you are using the most thorough, rigorous, well-written, studied, documented, tested, measured, and high-quality code out there.

To join us in bringing numerical computing to the web, get started by checking us out on GitHub, and please consider financially supporting stdlib. We greatly appreciate your continued support!

Shuffle

NPM version Build Status Coverage Status

Shuffle elements of an array-like object.

Usage

To use in Observable,

shuffle = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/random-shuffle@umd/browser.js' )

To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:

var shuffle = require( 'path/to/vendor/umd/random-shuffle/index.js' )

To include the bundle in a webpage,

<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-shuffle@umd/browser.js"></script>

If no recognized module system is present, access bundle contents via the global scope:

<script type="text/javascript">
(function () {
    window.shuffle;
})();
</script>

shuffle( arr[, options] )

Shuffles elements of an array-like object.

var arr = [ 1, 2, 3 ];
var out = shuffle( arr );
// e.g., returns [ 3, 1, 2 ]

The function accepts the following options:

  • copy: string indicating whether to return a copy (deep,shallow or none). Default: shallow.

By default, the function returns a shallow copy. To mutate the input array (e.g., when input values can be discarded or when optimizing memory usage), set copy to none.

var arr = [ 1, 2, 3 ];
var out = shuffle( arr, {
    'copy': 'none'
});
var bool = ( arr === out );
// returns true

To return a deep copy, set the copy option to deep.

var obj = {
    'beep': 'boop'
};
var arr = [ [ obj ], [ obj ], [ obj ] ];

// Deep copy:
var out = shuffle( arr, {
    'copy': 'deep'
});
var bool = ( arr === out );
// returns false

bool = ( arr[2] === out[2] );
// returns false

// Shallow copy:
out = shuffle( arr, {
    'copy': 'shallow'
});
bool = ( arr === out );
// returns false

bool = ( arr[2] === out[2] );
// returns true

shuffle.factory( [options] )

Returns a function to shuffle elements of array-like objects.

var myshuffle = shuffle.factory();

The function accepts the following options:

  • copy: string specifying the default copy option (deep,shallow or none). Default: shallow.
  • seed: pseudorandom number generator seed.

To seed the underlying pseudorandom number generator, set the seed option.

var myshuffle = shuffle.factory({
    'seed': 239
});

var out = myshuffle( [ 0, 1, 2, 3, 4 ] );
// e.g., returns [ 3, 4, 1, 0, 2 ]

By default, the returned functions create shallow copies when shuffling. To override the default copy strategy, set the copy option.

var myshuffle = shuffle.factory({
    'copy': 'none',
    'seed': 867
});

// Created shuffle function mutates input array by default:
var arr = [ 1, 2, 3, 4, 5, 6 ];
var out = myshuffle( arr );
var bool = ( arr === out );
// returns true

// Default option can be overridden:
arr = [ 1, 2, 3, 4 ];
out = myshuffle( arr, {
    'copy': 'shallow'
});
bool = ( arr === out );
// returns false

Examples

<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-shuffle@umd/browser.js"></script>
<script type="text/javascript">
(function () {

var result;
var data;
var i;

data = new Array( 20 );
for ( i = 0; i < data.length; i++ ) {
    data[ i ] = i;
}

for ( i = 0; i < 10; i++ ) {
    result = shuffle( data );
    console.log( result );
}

})();
</script>
</body>
</html>

See Also

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

Chat

License

See LICENSE.

Copyright

Copyright © 2016-2024. The Stdlib Authors.