Answers for "to sum an arraay is js"

array sum javascript

const arr = [1, 2, 3, 4];
const sum = arr.reduce((a, b) => a + b, 0);
// sum = 10

how to get sum array in javascript

let sub1 = (arr) => arr.reduce( (x,y) => x+y);

console.log(sub1([2, 4, 9]));
console.log(sub1([15, 200, 18, 0, 18, 18]));
console.log(sub1([100, 4, 17, 29, 81]));

how to sum variables to an array in javascript

function sumGrades(grades) {
    let sum =0;
    grades.forEach(function(grade){
        sum += grade;
    })
    return sum;
}

// Sample usage - do not modify
console.log(sumGrades([15, 5, 10])); // 30
console.log(sumGrades([12, 10, 13, 19])); // 54