Array Average in JavaScript

1// Method 1: Using for loop
2function averageLoop(arr) {
3    if (arr.length === 0) return 0;
4    
5    let sum = 0;
6    for (let i = 0; i < arr.length; i++) {
7        sum += arr[i];
8    }
9    return sum / arr.length;
10}
11
12let numbers = [10, 20, 30, 40, 50];
13console.log("Array:", numbers);
14console.log("Average:", averageLoop(numbers));
15
16// Method 2: Using reduce
17function averageReduce(arr) {
18    if (arr.length === 0) return 0;
19    
20    let sum = arr.reduce((acc, num) => acc + num, 0);
21    return sum / arr.length;
22}
23
24console.log("\nUsing reduce:", averageReduce([5, 10, 15, 20]));
25
26// Method 3: Using forEach
27function averageForEach(arr) {
28    if (arr.length === 0) return 0;
29    
30    let sum = 0;
31    arr.forEach(num => sum += num);
32    return sum / arr.length;
33}
34
35console.log("\nUsing forEach:", averageForEach([2, 4, 6, 8, 10]));
36
37// Method 4: One-liner with reduce
38const average = arr => arr.length ? arr.reduce((a, b) => a + b) / arr.length : 0;
39
40console.log("\nOne-liner:", average([1, 2, 3, 4, 5]));
41
42// Method 5: With precision
43function averagePrecise(arr, decimals = 2) {
44    if (arr.length === 0) return 0;
45    let avg = arr.reduce((a, b) => a + b) / arr.length;
46    return parseFloat(avg.toFixed(decimals));
47}
48
49console.log("\nWith precision:", averagePrecise([1, 2, 3], 2));