const sum = [1, 2, 3].reduce((partialSum, a) => partialSum + a, 0);

console.log(sum); // 6

const arrSum = arr => arr.reduce((a,b) => a + b, 0)

let numbers = [10,20,30,40,50];

let     sum = 0;

​

for(let i =0; i< numbers.length; i++) {

    sum += numbers[i];

}

console.log(sum);

​

// Output : 150

[1, 2, 3, 4].reduce((a, b) => a + b, 0)

​

// Output: 10

const sum = arr => arr.reduce((a, b) => a + b, 0);

const sumNums = (arr)=>{

    let sum=0;

    for (let t = 0; t < arr.length; t++) {

        if(typeof arr[t] == "number" ){

​

           sum = sum + arr[t] ;

        }

    }

    return sum;

}

​

//if you find this answer is useful ,

//upvote ⇑⇑ , so can the others benefit also . @mohammad alshraideh ( ͡~ ͜ʖ ͡°)

function getArraySum(a){

    var total=0;

    for(var i in a) { 

        total += a[i];

    }

    return total;

}

​

var payChecks = [123,155,134, 205, 105]; 

var weeklyPay= getArraySum(payChecks); //sums up to 722

let arr = [2, 4, 1, 3, 5];

let result = 0;

​

for (let i = 0; i < arr.length; i++) {

   result += arr[i];

}

​

console.log(result); // 15

let sum1 = (arr) => arr.reduce( (x,y) => x+y);

​

console.log(sum1([2, 4, 9]));

console.log(sum1([15, 200, 18, 0, 18, 18]));

console.log(sum1([100, 4, 17, 29, 81]));

const num = [1, 3, 1, 1] 

const reducer = (accumulator, currentValue) => accumulator + currentValue;

const sum = num.reduce(reducer);

console.log(sum)

// (1+3+1+1) = 6