How to use for of and for in loop In Javascript

Here, we will use the for of and for in loop and traverse each element of array and will increase size variable on each iteration by one.

Javascript

// Defining the array
let arr = [12, 4.7, 9, 10]

// Defining the length variable
let size = 0;

// Looping using for-in loop
for (let element in arr) {
size++;
}

// Printing the length
console.log(`Length by using for in loop ->; ${size}`)

// Reseting the value of variable
size = 0;

// Looping using for-or loop
for (let element of arr) {
size++;
}
// Printing the length
console.log(`Length by using for of loop ->; ${size}`)

Output

Length by using for in loop ->; 4
Length by using for of loop ->; 4

Explanation:

The above code defines an array arr and initializes a variable size to 0. It then iterates over the elements of the array using both for-in and for-of loops, incrementing size for each element. Finally, it prints the lengths obtained from both loops.