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5.3 Iterating Through Arrays

5.3 Iterating Through Arrays

Iterating Through Arrays

There are different ways to iterate through arrays.

All you need to choose a loop that best fits your needs.

Practice will help you determine what kind of loop you would want for a certain problem.

The general idea is that some kind of 0 based index is given to the array to return the value found in that location of the array.

The 0 based index would then be increased by a certain amount over a certain period of iterations.

Example

let arr = [1, 2, 3, 4];
for (let i = 0; i < arr.length; i++) {
    console.log(arr[i]);
}

// output:
// 1
// 2
// 3
// 4

What is happening here?

  • We create an array with values: 1, 2, 3, 4.
  • We then used a for loop that is set to stop after i < arr.length (the length of the array).
  • At each iteration, we console.log() the value found at that certain index in the array.

Alternative Example

💡

We can actually use a for each loop to accomplish the same thing!

let arr = [1, 2, 3, 4];
arr.forEach((num) => {
	console.log(num);
});

// output:
// 1
// 2
// 3
// 4

Practice

You can add practice problems here if you want. Follow the format below.

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