javascript - Sum of elements, differences between code -

i have 2 pieces of code both calculating sum of elements of array:

var sum = array.reduce(function(previousvalue, currentvalue) {     return previousvalue + currentvalue; }, 0);

var sum = 0; array.foreach(function(e) {     sum += e; });

are there differences between them beside different implementations? when better use one?

besides personal style preference, there difference in actual performance. 2 perform however.

if you're doing operation lot (or large arrays) consider using third way:

var sum = 0; (l = array.length; l--; ) { sum += array[l]; }

this way faster. check this performance test actual results.

note: gain speed if cache array length. instead of doing this:

for (var = 0; < array.length; i++) {...}

do this:

var l = array.length; (; l--; ) { ... }

or this:

for (l = array.length; l--;) { ... }

Error