JavaScript Array Reference

Explanation:

Stores multiple related values in one variable.

Array Properties

length

Returns the total number of elements in the array.

Explanation:

Returns 3 for three elements.

Creating Arrays

Explanation:

Creates an array with numeric values.

Accessing and Updating Elements

Explanation:

Accesses and updates elements using index positions.

Common Array Methods (Reference)

Add / Remove

• push() → add to end

• pop() → remove from end

• shift() → remove from start

• unshift() → add to start

Search

• includes() → check if value exists

• indexOf() → find index

• lastIndexOf() → find last index

• find() → find element by condition

• findIndex() → find index by condition

Iteration / Transformation

• forEach() → loop through elements

• map() → create new array

• filter() → filter elements

• reduce() → combine values

• some() → check any match

• every() → check all match

Sorting / Reordering

• sort() → sort elements

• reverse() → reverse array

Extract / Combine

• slice() → extract portion

• splice() → add/remove elements

• concat() → merge arrays

Mutating vs Non-Mutating Methods

Some methods change the original array, others return a new array.

Mutating Methods:
push(), pop(), shift(), unshift(), sort(), splice(), reverse()

Non-Mutating Methods:
map(), filter(), slice(), concat(), includes()

Common Mistakes with Arrays

• Forgetting that indexes start from 0

• Mutating arrays unintentionally

• Using map() when no new array is required

• Confusing slice() with splice()

Summary of JavaScript Array Reference

Conclusion

The JavaScript Array reference provides essential methods and properties to manage collections of data effectively. By understanding how to create arrays, access elements, and use built-in methods for searching, iterating, sorting, and transforming data, array handling becomes simple and powerful in JavaScript applications.