How to iterate an array in javascript

Question

I have an array like var arr = { 30,80,20,100 };

And now i want to iterate the above array and add the iterated individual values to one function return statement for example

function iterate()
{
    return "Hours" + arr[i];
}

I had tried in the following approach

function m()
{
    for(var i in arr)
    {
        s = arr[i];
    }
    document.write(s);
}

The above code will gives only one value i.e. last value in an array. But i want to iterate all values like

30---for first Iteration
80---for second Iteraton

Any help will be appreciated

Answer 1

Iterate over using the length property rather than a for ... in statement and write the array value from inside the loop.

for (var ii = 0, len = arr.length; ii < len; ii++) {
  document.write(arr[ii]);
}