A common task in Javascript is to iterate through the contents of an array. One way to do that is with a for loop. This code will output each element of the array arr to the console:

    var arr = [10,9,8,7,6];
    for (var i=0; i < arr.length; i++) {
       console.log(arr[i]);
    }

Remember that Arrays have zero-based numbering, which means the last index of the array is length - 1. Our condition for this loop is i < arr.length, which stops when i is at length - 1.