Объединения

Enter your regex: [0-4[6-8]] Enter input string to search: 0

I found the text "0" starting at index 0 and ending at index 1.

Enter your regex: [0-4[6-8]]

Enter input string to search: 5

No match found.

Enter your regex: [0-4[6-8]] Enter input string to search: 8

I found the text "8" starting at index 0 and ending at index 1.

Enter your regex: [0-4[6-8]]

Enter input string to search: 9

No match found.

Пересечения

Enter your regex: [0-9&&[345]] Enter input string to search: 3

I found the text "3" starting at index 0 and ending at index 1.

Enter your regex: [0-9&&[345]]

Enter input string to search: 6

No match found.

Enter your regex: [2-8&&[4-6]]

Enter input string to search: 3

No match found.

Enter your regex: [2-8&&[4-6]] Enter input string to search: 4

I found the text "4" starting at index 0 and ending at index 1.

Вычитание

Enter your regex: [0-9&&[^345]]

Enter input string to search: 2

I found the text "2" starting at index 0 and ending at index 1.

Enter your regex: [0-9&&[^345]]

Enter input string to search: 3

No match found.

Enter your regex: [0-9&&[^345]]

Enter input string to search: 4

No match found.

Enter your regex: [0-9&&[^345]]

Enter input string to search: 5

No match found.

Предопределенные классы

.	Любой символ
\d	Цифра, [0-9]
\D	Не цифра, [^0-9]
\s	Пробельный символ, [ \t\n\x0B\f\r]
\S	Не пробельный символ, [^\s]
\w	Символ слова [a-zA-Z_0-9]
\W	Не символ слова [^\w]

Примеры

Enter your regex: .

Enter input string to search: @

I found the text "@" starting at index 0 and ending at index 1.

Enter your regex: \d

Enter input string to search: 1

I found the text "1" starting at index 0 and ending at index 1.

Enter your regex: \d

Enter input string to search: a

No match found.

Enter your regex: \D

Enter input string to search: 1

No match found.

Квантификаторы

Квантификатор позволяет задать количество повторений

X?	Один или ни одного
X*	Ни одного, или неограниченно много
X+	Один или много
X{n}	n повторений
X{n,}	Как минимум n повторений
X{n,m}	Как минимум n, но не больше m

Квантификаторы

Enter your regex: a?

Enter input string to search:

I found the text "" starting at index 0 and ending at index 0.

Enter your regex: a*

Enter input string to search:

I found the text "" starting at index 0 and ending at index 0.

Enter your regex: a+

Enter input string to search:

No match found.

Совпадения нулевой длины

Enter your regex: a?

Enter input	string to search:	a
I found the	text "a" starting	at index 0 and ending at index
1.
I found the	text "" starting at index 1 and ending at index 1.
Enter your regex: a*
Enter input	string to search: a
I found the	text "a" starting at index 0 and ending at index
1.
I found the	text "" starting at index 1 and ending at index 1.
Enter your regex: a+
Enter input	string to search: a
I found the	text "a" starting at index 0 and ending at index
1.

Совпадения нулевой длины

Enter your regex: a?
Enter input	string to search: ababaaaab
I found the	text "a" starting	at	index 0 and ending at		index 1.
I found the	text "" starting at index 1 and			ending at index 1.
I found the	text "a" starting	at	index 2 and ending at		index 3.
I found the	text "" starting at index 3 and			ending at index 3.
I found the	text "a" starting	at	index 4 and ending at		index 5.
I found the	text "a" starting	at	index 5 and ending at		index 6.
I found the	text "a" starting	at	index 6 and ending at		index 7.
I found the	text "a" starting	at	index 7 and ending at		index 8.
I found the	text "" starting at index 8 and			ending at index 8.
I found the	text "" starting at index 9 and			ending at index 9.
Enter your regex: a*
Enter input	string to search: ababaaaab
I found the	text "a" starting at		index 0 and ending at		index 1.
I found the	text "" starting at index 1 and			ending at index 1.
I found the	text "a" starting at		index 2 and ending at		index 3.
I found the	text "" starting at index 3 and			ending at index 3.
I found the	text "aaaa" starting		at index 4	and ending	at index 8.
I found the	text "" starting at index 8 and			ending at index 8.
I found the	text "" starting at index 9 and			ending at index 9.

Квантификаторы

Enter your regex: a{3}

Enter input string to search: aa

No match found.

Enter your regex: a{3}

Enter input string to search: aaa

I found the text "aaa" starting at index 0 and ending at index 3.

Enter your regex: a{3}

Enter input string to search: aaaa

I found the text "aaa" starting at index 0 and ending at index 3.

Enter your regex: a{3,}

Enter input string to search: aaaaaaaaa

I found the text "aaaaaaaaa" starting at index 0 and ending at index 9.