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Pedro Ávila
Asked: 2020-03-25 07:55:11 +0800 CST 2020-03-25 07:55:11 +0800 CST

Sum elements of an Array in JavaScript

  • 772

I have an array which I want to add its elements but with the algorithm that I have it gives me an error.

var numeros = [1, 2, 3, 4, 5], suma = 0;
    forEach (numeros, function(numero){
        suma += numero;
    });
    console.log(suma);

Error: Uncaught ReferenceError: forEach is not defined

What is the correct way to do it?

And how would it be doing a For

for(var i = 0; i <= numeros.length; i++){
        numero = numeros[i];
        suma += numero;
    }

To compare both methods.

javascript

2 Answers

  1. you can do it like this:

    note: the Each or loop function is deprecated. it was replaced by for(let i in array)and for(let i of array)but thearray.prototype.forEach

    with reduce: 

    let numeros = [1, 2, 3, 4, 5];
let total = numeros.reduce((a, b) => a + b, 0);

console.log(total);

    with array.prototype.forEach :

    let total=0,numeros = [1, 2, 3, 4, 5];
numeros.forEach(function(a){total += a;});
console.log(total);

    with for of : 

    let total=0,numeros = [1, 2, 3, 4, 5];
for(let i of numeros) total+=i;
console.log(total);

    for classic:

    let total=0,numeros = [1, 2, 3, 4, 5];
for(let i = 0; i <= numeros.length; i++) total+=numeros[i];
console.log(total);

    • 19
  2. Best Answer

    Your mistake is that the syntax must be like this arreglo.forEach(), that is, the array through the name of the variable that contains it must access .the method with the dot syntax forEach()and then remove the name of the array that you put inside the loop; being that way

    var numeros = [1, 2, 3, 4, 5], suma = 0;
    numeros.forEach (function(numero){
        suma += numero;
    });
    console.log(suma);
    • 4