View: array_slice

Function:
Description: Returns elements specified by offset and length.
Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
function array_slice (arr, offst, lgth, preserve_keys) {
    // http://jsphp.co/jsphp/fn/view/array_slice
    // +   original by: Brett Zamir (http://brett-zamir.me)
    // -    depends on: is_int
    // +      input by: Brett Zamir (http://brett-zamir.me)
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // %          note: Relies on is_int because !isNaN accepts floats 
    // *     example 1: array_slice(["a", "b", "c", "d", "e"], 2, -1);
    // *     returns 1: {0: 'c', 1: 'd'}
    // *     example 2: array_slice(["a", "b", "c", "d", "e"], 2, -1, true);
    // *     returns 2: {2: 'c', 3: 'd'}
/*
    if ('callee' in arr && 'length' in arr) {
        arr = Array.prototype.slice.call(arr);
    }
    */

    var key = '';

    if (Object.prototype.toString.call(arr) !== '[object Array]' || 
        (preserve_keys && offst !== 0)) { // Assoc. array as input or if required as output
        var lgt = 0,
            newAssoc = {};
        for (key in arr) {
            //if (key !== 'length') {
            lgt += 1;
            newAssoc[key] = arr[key];
            //}
        }
        arr = newAssoc;

        offst = (offst < 0) ? lgt + offst : offst;
        lgth = lgth === undefined ? lgt : (lgth < 0) ? lgt + lgth - offst : lgth;

        var assoc = {};
        var start = false,
            it = -1,
            arrlgth = 0,
            no_pk_idx = 0;
        for (key in arr) {
            ++it;
            if (arrlgth >= lgth) {
                break;
            }
            if (it == offst) {
                start = true;
            }
            if (!start) {
                continue;
            }++arrlgth;
            if (this.is_int(key) && !preserve_keys) {
                assoc[no_pk_idx++] = arr[key];
            } else {
                assoc[key] = arr[key];
            }
        }
        //assoc.length = arrlgth; // Make as array-like object (though length will not be dynamic)
        return assoc;
    }

    if (lgth === undefined) {
        return arr.slice(offst);
    } else if (lgth >= 0) {
        return arr.slice(offst, offst + lgth);
    } else {
        return arr.slice(offst, lgth);
    }
}
Comment on array_slice version 37
Tests
Benchmark
[top]

Comments

There are no comments yet, be the first!

Please Login or Register to post comments.