forEach.js

const data = [5, 4, 3, 2, 1];

// Usage 1 - 
data.forEach(val => console.log("Usage 1", val));

// Usage 2 - Mutating(changing the array value inplace)
data.forEach((val, index) => {
  data[index] = val * val;
})
console.log("Inplace value changes, ", data);

// Functionality check on return value. 
const result = data.forEach((val) => {
  val*val;
})
console.log("Result of return value is, ", result);