Question

Is there anyway to merge arrays in javascript by ordering by index/position. I’m try to accomplish this and haven’t been able to find any examples of this.

var array1 = [1,2,3,4]
var array2 = [a,b,c,d]
var array3 = [!,@,#,$]

var merged array = [1,a,!,2,b,@,3,c,#,4,d,$]

I know you can use concat() to put one after the other.

Answer 1

This should work for arrays of ANY length:

var mergeArrays = function () {
    var arr = [],
        args = arr.slice.call(arguments),
        length = 0;

    for (var i = 0, len = args.length; i < len; i++) {
        length = args[i].length > length ? args[i].length : length;
    }

    for (i = 0; i < length; i++) {
        for (var j = 0; j < len; j++) {
            var value = args[j][i];

            if (value) {
                arr.push(value);
            }
        }
    }

    return arr;
};

Example:

var array1 = [1,2,3,4];
var array2 = ['a','b','c','d','e','f','g','h','i','j','k','l'];
var array3 = ['!','@','#','$','%','^','&','*','('];

mergeArrays(array1, array2, array3);
// outputs: [1, "a", "!", 2, "b", "@", 3, "c", "#", 4, "d", "$", "e", "%", "f", "^", "g", "&", "h", "*", "i", "(", "j", "k", "l"]

This would work also (a little more terse syntax):

var mergeArrays = function () {
    var arr = [],
        args = arr.slice.call(arguments),
        length = Math.max.apply(null, args.map(function (a) { return a.length; }));

    for (i = 0; i < length; i++) {
        for (var j = 0, len = args.length; j < len; j++) {
            var value = args[j][i];

            if (value) {
                arr.push(value);
            }
        }
    }

    return arr;
};