Implementation of JavaScript merge() function

Took 4 minutes 9 seconds to implement JavaScript merge() function for same length arrays. Here is the code snippet.

Function:

arr1 = ['bla', 'bla', 'bla'];

arr2 = ['ha', 'ha', 'ha'];

function merge(arr1, arr2) {

for (var i = 0; i < arr2.length; i++) {

arr1.push(arr2[i]);

}

}

merge(arr1, arr2);

document.write(arr1)

Result:

bla,bla,bla,ha,ha,ha