Array Method Help for Javascript

Question

The goal is to return the sum of the numbers in the array using the forEach method. What am I doing wrong?

list = [6,7,1,3,1,17,4,12,1,5,0,13,15]
function totalPoint(array) {
 let sum = 0;
 array.forEach(function(number){
 sum += number
 return sum
 })
}
totalPoint(list)

It should have the same result as this:

function totalPoints(array){
 let sum = 0;
 for (let i = 0; i < array.length; i++) {
 sum += array[i]
 }
return sum
}

• senthilbalaji: use reduce it is easier. array.reduce((total, curr) => total+=curr, 0);
• Carlos1232: when you do a forEach it doesnt return anything, what you should do is a normal for or use .reduce()
• senthilbalaji: reduce is when you wanted an accumulated result from the array like sum, product, string concat with a filter and what not! in this use case definitely is easier as you don't have to maintain any variable.
• ASDFGerte: For beginners, it somehow seems like a real problem, to realize, what function scope they are in, and accordingly, what the return counts for. So far, i assumed it's just people not really trying, but by the sheer amount of issues, i may have to reconsider. The problem is solely, that your return is for the callback of the forEach, and your totalPoint doesn't have any return. Simply move the return to the end of totalPoint.
• epascarello: It is no different than the for loop..... return needs to be outside the loop, exactly how you did it with the for loop.

Answer 1

Using forEach loop return sum should be outside forEach:

list = [6,7,1,3,1,17,4,12,1,5,0,13,15]
function totalPoint(array) {
 let sum = 0;
 array.forEach(function(number){
 sum += number;
 
 })
 return sum;
}
totalPoint(list)

Answer 2

For each does not return anything you need to return from function:

const array = [6,7,1,3,1,17,4,12,1,5,0,13,15]
function totalPoint(array) {
 let sum = 0;
 array.forEach(function(number){
 sum += number
 })
 return sum
}
console.log(totalPoint(array))

Better way is to use reduce

const array = [6,7,1,3,1,17,4,12,1,5,0,13,15]
function totalPoint(array) {
 return array.reduce((sum,number) => sum + number,0)
}
console.log(totalPoint(array))

• 3limin4t0r: I suggest using more descriptive names for the reduce callback. (sum, number) => sum + number is a lot more understandable than (prev, next) => prev + next.
• Shubham Verma: Make senses. Updated. Thanks!

Answer 3

You return inside the callback (which is useless), but not at the end of the method.

function totalPoint(array) {
 let sum = 0;
 array.forEach(function(number){
 sum += number
 });
 return sum;
}
list = [6,7,1,3,1,17,4,12,1,5,0,13,15]
console.log(totalPoint(list));

A simpler method would be to use Array#reduce:

function totalPoint(array) {
 return array.reduce((acc,curr)=>acc + curr, 0);
}
list = [6,7,1,3,1,17,4,12,1,5,0,13,15]
console.log(totalPoint(list));

Answer 4

You can use Array.prototype.reduce for a simple solution:

const numbers = [6, 7, 1, 3, 1, 17, 4, 12, 1, 5, 0, 13, 15];
const sum = numbers.reduce((runningTotal, number) => runningTotal += number, 0);
console.log(`The sum is ${sum}`);

Start with the accumulator initialized to 0 then, in the callback function, increment the accumulator by the next number in the array and return.