The code using Arrow function dosenot work to calculate average

Question

So I have written this code to calculate the average marks of students using Javascript. But for some reason it just gives the output as 242628302.6 always. I dont understand whats wrong with the code....Any help would be appreciated.

const marks = [];
var size = 5; //Maximum Array size

for (var i = 0; i < size; i++) { //Taking Input from user
   marks[i] = prompt('Enter Element ' + (i + 1));
}
const average = marks => marks.reduce((prev, curr) => prev + curr, 0) / marks.length;
const result = average(marks);
console.log(result);

Cast number on your inputs, it is being taken as strings – Nizar Zizoune Sep 10 '21 at 15:32 — Nizar Zizoune, Sep 10 '21 at 15:32

score 3 · Answer 1 · edited Sep 10 '21 at 15:36

3

Try with Number :

const marks = [];
var size = 5; //Maximum Array size

for (var i = 0; i < size; i++) { //Taking Input from user
     marks[i] = prompt('Enter Element ' + (i + 1));
}
const average = marks => marks.reduce((prev, curr) => Number(prev) + Number(curr), 0) / marks.length;
const result = average(marks);
console.log(result);

edited Sep 10 '21 at 15:36

Yang Yu

3,864
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answered Sep 10 '21 at 15:31

Nikola Pavicevic

13,800
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score 0 · Accepted Answer · answered Sep 10 '21 at 15:33

You need to convert the data type from string to Number since the prompt method return type is a string.

const marks = [];
                var size = 5; //Maximum Array size

                for (var i = 0; i < size; i++) { //Taking Input from user
                    marks[i] = prompt('Enter Element ' + (i + 1));
                }
                const average = marks => marks.reduce((prev, curr) => prev + Number(curr), 0) / marks.length;
                const result = average(marks);
                console.log(result);

The code using Arrow function dosenot work to calculate average

2 Answers2