when to use reduce and reduceRight?

Question

Can you describe this for me?

var arr, total;
arr = [1, 2, 3, 4, 5];
total = arr.reduce(function(previous, current) {
return previous + current;
});
// total         


        

Answer 1

The only thing is order of computation. Reduce does it 'left to right', reduceRight does it 'right to left'. See the following example: