Test case details

Preparation Code

<script>   var a;   var prependArray = function(value, oldArray) {    var i, len = oldArray.length + 1,        newArray = new Array(len);    newArray[0] = value;    for (i = 0; i < len; ++i) {     newArray.push(oldArray[i]);    }    return newArray;   } </script>
a = [1, 2, 3, 4];

Test cases

Test #1

a.unshift(0);

Test #2

prependArray(0, a);

Test #3

a.slice(0).unshift(0);

Test #4

a.splice(0,0,0);