Random Array

// Run through each index and assign random number
for (var array=[], i = 0; i < 4; ++i) array[i] = i;

function shuffle(array) {
    var tmp, current, top = array.length;

    if(top) while(--top) {
        current = Math.floor(Math.random() * (top + 1));
        tmp = array[current];
        array[current] = array[top];
        array[top] = tmp;
    }
    return array;
}

// Generate and print array
var array = shuffle(array);
console.log(array);