Course “JS: Arrays”
Course updated on April 29, 2025
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What's included
Description
Arrays are the key structure to organizing data into collections. Displaying courses on Hexlet or Google search results is based on them. In contrast to primitive data types, arrays require additional knowledge. A significant part of algorithmic tasks operates with nothing else but arrays. That's why we devote an entire course to them. Mastery of arrays is the foundation upon which everything else is built.
You will learn
- Define and manage arrays in code
- Build and manipulate arrays in loops
- Apply basic algorithms and evaluate their complexity
- Use spread, rest syntax and destructuring
Syllabus
1 | About the course Learn about the course, its structure, objectives, and goals |
2 | Syntax Learn array syntax |
3 | Modification Get an overview of the main methods of array modification |
4 | Checking a value exists Consider common mistakes when working with arrays: overriding, accessing a non-existent key |
5 | for loop Learn to use the for loop for arrays |
6 | References Introduce the concept of "reference data type" and learn how to handle arrays in functions correctly |
7 | Aggregation Learn data aggregation |
8 | for...of loop Learn a simple way to iterate over an array |
9 | Deleting array elements Learn the right and wrong ways to delete elements |
10 | Control statements Learn how the `break` and `continue` work |
11 | Nested arrays Learn the syntax for creating and updating nested arrays |
12 | Generating strings with a loop Learn how to build strings efficiently |
13 | Converting strings into arrays Learn how to process strings using arrays |
14 | Nested loops Learn how to handle loop nesting |
15 | Set Theory Embrace the beauty |
16 | Sorting arrays Learn the basic sort algorithms |
17 | Stack Meet one of the most fundamental data structures |
18 | Big O Learn how to evaluate the complexity of algorithms |
19 | Destructuring Learn to decompose an array into parts |
20 | Rest syntax and destructuring Learn how to "condense" data into an array |
21 | Spread syntax and creating new arrays Learn how to apply the spread syntax (which "expands" an array) to arrays |
22 | Arrays in computer memory Get to know what arrays are in real-world |
Challenges
1 | Matrix mirroring |
2 | Ascending sequence |
3 | Reverse Polish notation |
4 | Length of last word |
5 | Snail |
6 | Sea Battle |
7 | Sum of intervals |
8 | Pascal's Triangle |
9 | Compare versions |
10 | Chunking |
11 | Summary Ranges |
12 | Matrix Multiplication |
13 | Hamming weight |
14 | Matrix rotation |
15 | Longest substring |
- Run code right in the browser
- Lifetime access
- Learn at your own pace
Access this and all courses with a subscription