I want to calculate sum with forEach array function in JavaScript. But I don't get what I want.
function sum(...args) { args.forEach(arg => { var total = 0; total += arg; console.log(total); }); } sum(1, 3); How to get total with forEach, or use reduce method?
You may better use Array#reduce, because it is made for that kind of purpose.
It takes a start value, of if not given, it take the first two elements of the array and reduces the array literally to a single value. If the array is empty and no start value is supplied, it throws an error.
function sum(...args) { return args.reduce((total, arg) => total + arg, 0); } console.log(sum(1, 3)); console.log(sum(1)); console.log(sum());You should put total outside forEach loop:
function sum(...args) { var total = 0; args.forEach(arg => { total += arg; }); console.log(total); } sum(1, 3); You have to move the total=0; out of the loop - it is being reset to 0 on each iteration
function sum(...args) { var total = 0; args.forEach(arg => { total += arg; console.log(total); }); } sum(1, 3); // gives 1, 4 or in other words 0+1=1 then 1+3=4function sum(...args) { var total = 0; args.forEach(arg => { total += arg; console.log(total); }); } sum(1, 3); 
forEach function.function sum(...args) { return args.reduce((total, amount) => total + amount); } console.log(sum(1,3));