I wanted to create an array with length depending on the users input and then tried to find the sum of all the numbers in the array

<!DOCTYPE html>
<html>
    <body>
        <script>
            var cases=prompt("number of ingredients");
            var i=0;
            var a=[];
            while (i<cases){
                i=i+1;
                var cost=prompt("cost of this ingredient");
                a.push(cost);
            }
            alert(a);
            var t=a.length;
            var sum=0;
            var j=0;
            while (j<t-1){
                var sum=sum+a[j];
                j=j+1;
            }
            alert(sum);
        </script>
    </body>
</html>

Want to create an array depending on users input in 'cases'. Then tried finding the sum of all numbers in the array 'a'. But its not giving me the answer. Whats wrong? Help is appreciated.

Solution

You should parse the input to an integer, otherwise it will be treated as string. Also you need node to declare sum variable twice. Variable t is also not needed.

<!DOCTYPE html>
<html>
<body>
    <script>
        var cases=prompt("Number of ingredients");
        var i = 0;
        var a = [];
        while (i < cases){
        var cost = prompt("Cost of this ingredient");
        a[i] = parseInt(cost);
            i = i + 1;
        }
        var sum=0;
        var j=0;
        while (j < a.length){
            sum=sum+a[j];
            j=j+1;
        }
        alert(sum);
    </script>
</body>