loop in array object

Question

I have one array object
I want to sum scores field in all items with reduce
but i got wrong result what is reason?

My code:
const obj = [
{ name: "a", family: "e", score: 10 },
{ name: "b", family: "f", score: 5 },
{ name: "c", family: "g", score: 3 },
{ name: "d", family: "h", score: 19 }
];

document.getElementById("p2").innerHTML = obj.reduce(myFunction);

function myFunction(total, value) {
return total + value.score;
}

"p2" is a <p> tag.

Link:
https://code.sololearn.com/WvV6p7E0TN2U

Answer 1

<total> in myFunction is the accumulator, and it is a Number, initialized by zero, not an object. You only need to add <value.score> to <total> as you did in your post Description.

return total + value.score; // correct
//return total.score + value.score;
//wrong

Answer 2

You can link your code link this:
Go to Code section, click +, select the programming language, insert your code, save.
Come back to the thread, click +, Insert Code, sort for My Code Bits, select your code.

This way other users can test your code.

Answer 3

Apart from the function that handles the accumulation (reduction), you also need to provide an initial accumulator value, which is the second argument to be given to reduce()

obj.reduce( myFunction, 0 );

Here initial accumulator value will be zero (second argument). reduce() calls myFunction for each element, and assign the value returned by myFunction to the accumulator.

Answer 4

by initial accumulator value got NaN also.

Answer 5

ok thanks