# Sum of prime numbers between a range - JavaScript

We are required to write a JavaScript function that takes in two numbers, say a and b and returns the sum of all the prime numbers that fall between a and b. We should include a and b if they are prime as well.

## Example

Following is the code −

const num1 = 45;
const num2 = 345;
const isPrime = n => {
if (n===1){
return false;
}else if(n === 2){
return true;
}else{
for(let x = 2; x < n; x++){
if(n % x === 0){
return false;
}
}
return true;
};
};
const primeBetween = (a, b) => {
const res = [];
while(a <= b){
if(isPrime(a)){
res.push(a);
};
a++;
};
return res;
};
console.log(primeBetween(num1, num2));

## Output

Following is the output in the console −

[
47,  53,  59,  61,  67,  71,  73,  79,  83,
89,  97, 101, 103, 107, 109, 113, 127, 131,
137, 139, 149, 151, 157, 163, 167, 173, 179,
181, 191, 193, 197, 199, 211, 223, 227, 229,
233, 239, 241, 251, 257, 263, 269, 271, 277,
281, 283, 293, 307, 311, 313, 317, 331, 337
]

Updated on: 16-Sep-2020

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