Notice: This page requires JavaScript to function properly.
Please enable JavaScript in your browser settings or update your browser.
Mastering Arrays Sum Up | Mastering Arrays
JavaScript Data Structures

Mastering Arrays Sum UpMastering Arrays Sum Up

Arrays are data structures used to store and manipulate collections of values.

Creating Arrays

  • Arrays in JavaScript are created using square brackets [] and are known as array literals;
  • Commas separate elements within the array.

Accessing Array Elements

  • Array indices start at 0, meaning the first element has an index of 0, the second element has an index of 1, and so on;
  • Specific elements within an array can be accessed by using square brackets with the element's index.

Modifying Array Elements

Array elements can be changed by accessing them through their index and assigning a new value.


Array Length

The length property of an array represents the number of elements it contains. It automatically adjusts when elements are added or removed.


Finding the Last Element

To retrieve the value of the last element in an array, we can calculate its index using the array's length, which is array.length - 1.


For Loop

  • The for loop is used for iterating over an array element by element;
  • It uses a loop counter variable (e.g., i) to access each element by index;
  • The loop continues as long as the counter is less than the array's length;
  • It's a fundamental tool for array iteration.

For...of Loop

  • The for...of loop is a more modern and concise way to iterate over arrays;
  • It automatically handles the loop counter and provides direct access to each element's value;
  • It simplifies array iteration, making the code cleaner and more readable.

Let's keep going

Select the correct answer

Everything was clear?

Section 4. Chapter 9
course content

Course Content

JavaScript Data Structures

Mastering Arrays Sum UpMastering Arrays Sum Up

Arrays are data structures used to store and manipulate collections of values.

Creating Arrays

  • Arrays in JavaScript are created using square brackets [] and are known as array literals;
  • Commas separate elements within the array.

Accessing Array Elements

  • Array indices start at 0, meaning the first element has an index of 0, the second element has an index of 1, and so on;
  • Specific elements within an array can be accessed by using square brackets with the element's index.

Modifying Array Elements

Array elements can be changed by accessing them through their index and assigning a new value.


Array Length

The length property of an array represents the number of elements it contains. It automatically adjusts when elements are added or removed.


Finding the Last Element

To retrieve the value of the last element in an array, we can calculate its index using the array's length, which is array.length - 1.


For Loop

  • The for loop is used for iterating over an array element by element;
  • It uses a loop counter variable (e.g., i) to access each element by index;
  • The loop continues as long as the counter is less than the array's length;
  • It's a fundamental tool for array iteration.

For...of Loop

  • The for...of loop is a more modern and concise way to iterate over arrays;
  • It automatically handles the loop counter and provides direct access to each element's value;
  • It simplifies array iteration, making the code cleaner and more readable.

Let's keep going

Select the correct answer

Everything was clear?

Section 4. Chapter 9
some-alt