Sum of n Natural Numbers in JavaScript

1// Method 1: Using for loop
2let n = 10;
3let sum = 0;
4
5for (let i = 1; i <= n; i++) {
6    sum += i;
7}
8
9console.log("Sum of first", n, "natural numbers:", sum);
10
11// Method 2: Using formula (n × (n + 1)) / 2
12let num = 10;
13let sumFormula = (num * (num + 1)) / 2;
14console.log("Using formula:", sumFormula);
15
16// Method 3: Using while loop
17let number = 10;
18let total = 0;
19let counter = 1;
20
21while (counter <= number) {
22    total += counter;
23    counter++;
24}
25
26console.log("Using while loop:", total);
27
28// Method 4: Using function
29function sumNaturalNumbers(n) {
30    let sum = 0;
31    for (let i = 1; i <= n; i++) {
32        sum += i;
33    }
34    return sum;
35}
36
37console.log("Using function:", sumNaturalNumbers(10));
38
39// Method 5: Using reduce (functional approach)
40function sumNaturalNumbersReduce(n) {
41    return Array.from({length: n}, (_, i) => i + 1)
42                 .reduce((sum, num) => sum + num, 0);
43}
44
45console.log("Using reduce:", sumNaturalNumbersReduce(10));