20241202_1 JavaScript Regular Expressions

A regular expression is a sequence of characters that forms a search pattern.

When you search for data in a text, you can use this search pattern to describe what you are searching for.

A regular expression can be a single character, or a more complicated pattern.

Regular expressions can be used to perform all types of text search and text replace operations.

 

/pattern/modifiers;

String search() With a String

 text.search("test");

String search() With a Regular Expression

text.search(/test/i);

String replace() With a String

text.replace("MS", "test");

String replace() With a Regular Expression

text.replace(/microsoft/i, " test ");

 

Regular Expression Modifiers

Modifier	Description
i	Perform case-insensitive matching
g	Perform a global match (find all)
m	Perform multiline matching
d	Perform start and end matching

 

Regular Expression Patterns

Expression	Description
[abc]	Find any of the characters between the brackets
[0-9]	Find any of the digits between the brackets
(x|y)	Find any of the alternatives separated with |