Skip to main content

forEach Method

This is an array iteration method that is used as a replacement for the for and for...of loops when working with a data collection.

array.forEach(function callback(element, index, array) {
  // Callback body
});
  • Iterates over an array element by element.
  • Calls a callback function for each element of the array.
  • Returns nothing.

Callback arguments are the value of the current element element, its index index and the original array. You can declare only those parameters that are required – most often this is an element – but never forget about their order.

const numbers = [5, 10, 15, 20, 25];

// Classic for
for (let i = 0; i < numbers.length; i += 1) {
  console.log(`Index ${i}, value ${numbers[i]}`);
}

// Iterating forEach
numbers.forEach(function (number, index) {
  console.log(`Index ${index}, value ${number}`);
});

The only case where you should use for or for...of loops to iterate over an array is a task with loop interruption. You cannot interrupt the execution of the forEach method, as it always iterates over the array to the end.