Different ways to sum for an array of numbers in javascript with example

This article shows multiple ways to return the sum for an array of numbers in Javascript.

let’s declare an array as input

var myarray = [7, 8, 1, 9];

Output:

7+8+1+9=25

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Sum of an array of numbers in javascript

use for index loop

for index, the loop is a basic loop in Any programming language.

It iterates an array using an index starting from zero until the length of the array is reached.

A temporary variable is created to sum each iterate array value and store it.

Here is an example code

var myarray = [7, 8, 1, 9];
var result = 0;
for (var i = 0; i < myarray.length; i++) {
  result += myarray[i];
}
console.log(result); //25

use the for-of loop ES6 provides a for-of loop to iterate an array of elements in another way.

Syntax:

for(index of array){
    get element using array[i] syntax
}

Here is an example

var myarray = [7, 8, 1, 9];
var sum = 0;
for (var k in myarray) {
  sum += myarray[k];
}
console.log(sum);

Output:

use a forEach loop

Another way to iterate an array in javascript using the forEach loop. The forEach loop accepts a callback with each element. The callback can be a normal function or an arrow function in ES6. Here is an example.

let result = 0;
myarra.forEach((item) => {
  result += item;
});
console.log(result); // 25

use the lodash sum function

if you are using lodash in your project, It provides the sum() function that returns the addition of numbers in an array.

Here is a lodash sum function example.

var myarray = [7, 8, 1, 9];
result = _.sum(myarray);
console.log(result); // 25

use array reduce function

Array provides reduce function and reduces the array elements.

It accepts a callback function.

Written call back function with arrow syntax in ES6 to the sum of the numbers.

Here is an example code

var myarray = [7, 8, 1, 9];

const sum = (first, second) => first + second;
const result = myarray.reduce(sum);
console.log(result); // 25

Conclusion

As a result, Shown multiple ways to the addition of numbers to an array.