two dimensional array horizontal average output

Question

I am stuck with a problem and i don\'t know how to put this in a for loop. I need the hotizontal average of the next matrix:

1 2 3 4 5

5 4 3 2 1

3 2 1 4 5


        

Answer 1

Method :

var dArray = [[1, 2, 3, 4, 5],[5, 4, 3, 2, 1],[3, 2, 1, 4, 5]];
alert(dArray.map(function (a) {
    return (a.reduce(function (x, y) {return (x + y);})/a.length);
}));

Implementation:

<div id="matrix"></div>
<script>
    var dArray = [[1, 2, 3, 4, 5],[5, 4, 3, 2, 1],[3, 2, 1, 4, 5]];
    var buffer='';
    dArray.map(function (a) {
        buffer+= a.toString()+","+ (a.reduce(function (x, y) {return (x + y);})/a.length)+"<br/>";
    });
    document.addEventListener('DOMContentLoaded',function(){
        document.getElementById('matrix').innerHTML=buffer;
    },false);
</script>