Fastest way to calculate the sum of array elements

Question

I'm trying to find the fastest way to calculate the sum of elements contained in an array.
I managed to do it using eval(), but i consider eval as evil.

var arr = [10,20,30,40,50];
console.log( eval( arr.join('+') ) ); //logs 150

Is there a better way to do it other than using a for loop ?

I was thinking more about something like that, but it doesn't work:

var arr = [10,20,30,40,50];  

console.log( new Number( arr.join('+') ) ); //logs a Number Object  

console.log( new Number( arr.join('+') ).toString() ); //logs NaN

Answer 1

If supported you can use the reduce method of Array

var arr = [10, 20, 30, 40, 50];

console.log(arr.reduce(function(prev, cur) {
    return prev + cur;
}));

Answer 2

The best way is using a for loop. Is not the shortest, but is the best.