Regular expression syntax examples

In order to give you a quick reference to the different patterns and what they will match, here's a comprehensive table of all we've covered. Column one contains example expressions, and column two contains what that expression will match.

Expr

Will match...

foo

the string "foo"

^foo

"foo" at the start of a line

foo$

"foo" at the end of a line

^foo$

"foo" when it is alone on a line

[Ff]oo

"Foo" or "foo"

[abc]

a, b, or c

[^abc]

d, e, f, g, h, etc - everything that is not a, b, or c (^ is "not" inside sets)

[A-Z]

any uppercase letter

[a-z]

any lowercase letter

[A-Za-z]

any letter

[A-Za-z0-9]

any letter of number

[A-Z]+

one or more uppercase letters

[A-Z]*

zero or more uppercase letters

[A-Z]?

zero or one uppercase letters

[A-Z]{3}

3 uppercase letters

[A-Z]{3,}

a minimum of 3 uppercase letters

[A-Z]{1,3}

1-3 uppercase letters

[^0-9]

any non-numeric character

[^0-9A-Za-z]

any symbol (not a number or a letter)

Fo*

F, Fo, Foo, Fooo, Foooo, etc

Fo+

Fo, Foo, Fooo, Foooo, etc

Fo?

F, Fo

.

any character except \n (new line)

\b

a word boundary. E.g. te\b matches the "te" in "late", but not the "te" in "tell".

\B

a non-word boundary. "te\B" matches the "te" in "tell" but not the "te" in "late".

\n

new line character

\s

any whitespace (new line, space, tab, etc)

\S

any non-whitespace character

 

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