You don’t need to loop through each pair and add them in recursion. Just use if statement as below example.
Sum of numbers from 1 to n Examples in JS
Let’s see HTML example code:-
Sum of numbers from 1 to n JavaScript recursion
Check the value and if truthy return n plus the sum of n - 1
if the value is smaller than one and returns zero in this case, otherwise the result of the actual value plus the result of calling sum function with a decrement value.
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
function sum(n) {
if (n < 1) return 0;
return n + sum(n - 1);
}
console.log(sum(3));
</script>
</body>
</html>Output:
Without Recursion Example code
Adding numbers between one and a given number without recursion in JavaScript:-
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
function sumNums (num) {
let array = [];
for (let i = 0; i <= num; i++) {
array.push(i);
}
return array.reduce((a, b) => a + b);
}
console.log(sumNums(10));
</script>
</body>
</html>Output:
Do comment if you have any doubts and suggestion on this topic.
Note: The All JS Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version