javascript - Function to add up all the numbers from 1 to num -

i think there better version solution. solution working fine. didn't juggling of values using loop.

but particularly wondering, if there nice , 1 line solution getting values in array entered number function.

function simpleadding(num) {   var fnum = [];   (var = 1; <= num; i++) {     fnum.push(i);   }   return fnum.reduce(function(prevvalue, currentvalue) {     return prevvalue + currentvalue;   }) } 

i think there better version solution.

use formula

function simpleadding(num) {     return num * (num+1) /2; } 

if there nice , 1 line solution getting values in array entered number function

function simpleadding(num) {   var fnum = new array(num).join().split(',').map(function(item, index){ return ++index;});    return fnum.reduce(function(prevvalue, currentvalue) {     return prevvalue + currentvalue;   }) }