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Split element entries into two groups according to a predicate function.
To use in Observable,
bifurcateEntriesBy = require( 'https://cdn.jsdelivr.net/gh/stdlib-js/array-base-bifurcate-entries-by@umd/browser.js' )To vendor stdlib functionality and avoid installing dependency trees for Node.js, you can use the UMD server build:
var bifurcateEntriesBy = require( 'path/to/vendor/umd/array-base-bifurcate-entries-by/index.js' )To include the bundle in a webpage,
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-base-bifurcate-entries-by@umd/browser.js"></script>If no recognized module system is present, access bundle contents via the global scope:
<script type="text/javascript">
(function () {
window.bifurcateEntriesBy;
})();
</script>Splits element entries into two groups according to a predicate function.
function predicate( v ) {
return v[ 0 ] === 'b';
}
var x = [ 'beep', 'boop', 'foo', 'bar' ];
var out = bifurcateEntriesBy( x, predicate );
// returns [ [ [ 0, 'beep' ], [ 1, 'boop' ], [ 3, 'bar' ] ], [ [ 2, 'foo' ] ] ]A predicate function is provided the following arguments:
- value: current array element.
- index: current array element index.
- arr: input array.
To set the predicate function execution context, provide a thisArg.
function predicate( v ) {
this.count += 1;
return v[ 0 ] === 'b';
}
var x = [ 'beep', 'boop', 'foo', 'bar' ];
var context = {
'count': 0
};
var out = bifurcateEntriesBy( x, predicate, context );
// returns [ [ [ 0, 'beep' ], [ 1, 'boop' ], [ 3, 'bar' ] ], [ [ 2, 'foo' ] ] ]
var cnt = context.count;
// returns 4<!DOCTYPE html>
<html lang="en">
<body>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/random-array-discrete-uniform@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-base-take-indexed@umd/browser.js"></script>
<script type="text/javascript" src="https://cdn.jsdelivr.net/gh/stdlib-js/array-base-bifurcate-entries-by@umd/browser.js"></script>
<script type="text/javascript">
(function () {
function predicate( v ) {
// Use the first letter of each element to define groups:
return v[ 0 ] === 'b';
}
// Define an initial array of values:
var values = [ 'beep', 'boop', 'foo', 'bar', 'woot', 'woot' ];
// Sample from the initial array to generate a random collection:
var indices = discreteUniform( 100, 0, values.length-1, {
'dtype': 'generic'
});
var x = take( values, indices );
// returns [...]
// Split the values:
var out = bifurcateEntriesBy( x, predicate );
// returns [...]
console.log( out );
})();
</script>
</body>
</html>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 © 2016-2025. The Stdlib Authors.