JavaScript array_chunk

Split array into chunks

function array_chunk (input, size, preserve_keys) {
    // Split array into chunks  
    // 
    // version: 1109.2015
    // discuss at: http://phpjs.org/functions/array_chunk    // +   original by: Carlos R. L. Rodrigues (http://www.jsfromhell.com)
    // +   improved by: Brett Zamir (http://brett-zamir.me)
    // %        note 1: Important note: Per the ECMAScript specification, objects may not always iterate in a predictable order
    // *     example 1: array_chunk(['Kevin', 'van', 'Zonneveld'], 2);
    // *     returns 1: [['Kevin', 'van'], ['Zonneveld']]    // *     example 2: array_chunk(['Kevin', 'van', 'Zonneveld'], 2, true);
    // *     returns 2: [{0:'Kevin', 1:'van'}, {2: 'Zonneveld'}]
    // *     example 3: array_chunk({1:'Kevin', 2:'van', 3:'Zonneveld'}, 2);
    // *     returns 3: [['Kevin', 'van'], ['Zonneveld']]
    // *     example 4: array_chunk({1:'Kevin', 2:'van', 3:'Zonneveld'}, 2, true);    // *     returns 4: [{1: 'Kevin', 2: 'van'}, {3: 'Zonneveld'}]
    
    var x, p = '', i = 0, c = -1, l = input.length || 0, n = [];
    
    if (size < 1) {        return null;
    }
 
    if (Object.prototype.toString.call(input) === '[object Array]') {
        if (preserve_keys) {            while (i < l) {
                (x = i % size) ? n[c][i] = input[i] : n[++c] = {}, n[c][i] = input[i];
                i++;
            }
        }        else {
            while (i < l) {
                (x = i % size) ? n[c][x] = input[i] : n[++c] = [input[i]];
                i++;
            }        }
    }
    else {
        if (preserve_keys) {
            for (p in input) {                if (input.hasOwnProperty(p)) {
                    (x = i % size) ? n[c][p] = input[p] : n[++c] = {}, n[c][p] = input[p];
                    i++;
                }
            }        }
        else {
            for (p in input) {
                if (input.hasOwnProperty(p)) {
                    (x = i % size) ? n[c][x] = input[p] : n[++c] = [input[p]];                    i++;
                }
            }
        }
    }    return n;
}

external links: original PHP docs | raw js source

Examples

» Example 1

Running

1	array_chunk(['Kevin', 'van', 'Zonneveld'], 2);

Should return

1	[['Kevin', 'van'], ['Zonneveld']]

» Example 2

Running

1	array_chunk(['Kevin', 'van', 'Zonneveld'], 2, true);

Should return

1	[{0:'Kevin', 1:'van'}, {2: 'Zonneveld'}]

Dependencies

No dependencies, you can use this function standalone.

Open syntax issues

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