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Learn/JavaScript/Working with Data
JavaScript•Working with Data

RegExp Character Classes

Flash cards

Review the key moves

1/4
Core idea

What is the main idea behind RegExp Character Classes?

Lesson checks

Practice each idea before moving on

Short Mimo-style checks built from this lesson's code, terms, and sequence.

1Quick choice

Which statement best captures the main point of this lesson?

2Fill blank

Complete the missing token from the example code.

// ___ Digits
3Order

Put the learning moves in the order that makes the concept easiest to apply.

Regular Expression Methods
JavaScript Regex Character Classes
RegExp Character Classes

Character Classes are characters enclosed in square brackets [] .

A character class matches any character from a set within brackets:

// Match Digits
const pattern = /[0-9]/;

JavaScript Regex Character Classes

ClassDescription
[a]Matches the character between the brackets
[^a]Matches all characters NOT between the brackets
[abc]Matches all characters between the brackets
[^abc]Matches all characters NOT between the brackets
[a-z]Matches all characters in the range from a to z
[^a-z]Matches all characters NOT in the range from a to z
[0-9]Matches all characters in the range from 0 to 9

Example [HW]

let text = "Hello World!";
const pattern = /[HW]/g;
let result = text.match(pattern);

Example [A-Z]

let text = "This is W3School";
const pattern = /[A-Z]/g;
let result = text.match(pattern);

Example [1234]

let text = "123456789";
const pattern = /[1234]/g;
let result = text.match(pattern);

Example [1-4]

let text = "123456789";
const pattern = /[1-4]/g;
let result = text.match(pattern);

[01234] is the same as [0-4]

[abcde] is the same as [a-e]

Regular Expression Methods

Regular Expression Search and Replace can be done with different methods.

String Methods

MethodDescription
match( regex )Returns an Array of results
matchAll( regex )Returns an Iterator of results
replace( regex )Returns a new String
replaceAll( regex )Returns a new String
search( regex )Returns the index of the first match
split( regex )Returns an Array of results

RegExp Methods

MethodDescription
regex .exec()Returns an Iterator of results
regex .test()Returns true or false

See Also

JavaScript RegExp Flags

JavaScript RegExp Meta Characters

JavaScript RegExp Assertions

JavaScript RegExp Quantifiers

JavaScript RegExp Patterns

JavaScript RegExp Objects

JavaScript RegExp Methods

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JavaScript WeakMap

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JavaScript String Search