# JavaScript: find the sum of all odd numbers below one given number :

To find the sum of all odd numbers less than one specific number, we need to check if a number is odd or not for all numbers less than that number. If odd is found, we will add it to a final *sum* variable. This *sum* variable will hold the total sum of all numbers and it should be initialized as *0*.

## Javascript program :

The javascript program to find the sum of all odd numbers less than a given number looks like as below :

```
function isOdd(n) {
return Boolean(n % 2);
}
function findSum(no) {
let sum = 0;
for (var i = 0; i < no; i++) {
if (isOdd(i)) {
sum += i;
}
}
return sum;
}
console.log(findSum(100));
```

### Explanation :

- We have two functions here.
*findSum*and*isOdd*. *findSum*is the main function to find the sum. It takes one number and returns the sum.*isOdd*takes one number and returns one*Boolean*value based on the number is divisible by*2*or not.*sum*variable is used to hold the sum of all odd numbers.- One for loop runs from
*i = 0*to*i < no*and checks for each number if it is odd or not.*isOdd*is used to check for that. - If the current number is
*odd*, this number is added to*sum*. - Finally, the value of
*sum*is returned from*findSum*

In this example, we are finding out the sum of all odd numbers less than *100*, but we can use this same program to find out for any user given number.