JavaScript: Looping through arrays of arrays made easy

If you are working with complex data structures in JavaScript, you may find yourself needing to loop through arrays of arrays. This can be a bit tricky, but fortunately there are some simple techniques you can use to make the process easier.

One of the most straightforward ways to loop through an array of arrays is to use nested for loops. The outer loop will iterate over the main array, and the inner loop will iterate over each sub-array. Here's an example:

const arr = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

for (let i = 0; i < arr.length; i++) {
  for (let j = 0; j < arr[i].length; j++) {
    console.log(arr[i][j]);
  }
}

In this example, the outer loop iterates over the main array, and the inner loop iterates over each sub-array. Within the inner loop, we can access each element of the sub-array using the square bracket notation.

Another technique you can use is the forEach method. This method is available on arrays in JavaScript, and allows you to execute a function for each element in the array. Here's an example:

const arr = [
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9]
];

arr.forEach(subArr => {
  subArr.forEach(element => {
    console.log(element);
  });
});

In this example, we're using the forEach method to loop through each sub-array in the main array, and then to loop through each element within each sub-array.

These are just a couple of the techniques you can use to loop through arrays of arrays in JavaScript. With a bit of practice, you'll find that it becomes much easier to work with complex data structures in your JavaScript code.