regular expression in php
- Thread starter siec
- Start date
jackkalls
New member
Regular expressions are nothing more than a sequence or pattern of characters itself. They provide the foundation for pattern-matching functionality.
Using regular expression you can search a particular string inside a another string, you can replace one string by another string and you can split a string into many chunks.
PHP offers functions specific to two sets of regular expression functions, each corresponding to a certain type of regular expression. You can use any of them based on your comfort.
POSIX Regular Expressions
PERL Style Regular Expressions
POSIX Regular Expressions:
The structure of a POSIX regular expression is not dissimilar to that of a typical arithmetic expression: various elements (operators) are combined to form more complex expressions.
The simplest regular expression is one that matches a single character, such as g, inside strings such as g, haggle, or bag.
Lets give explaination for few concepts being used in POSIX regular expression. After that we will introduce you wih regular expression related functions.
Brackets
Brackets ([]) have a special meaning when used in the context of regular expressions. They are used to find a range of characters.
Expression Description
[0-9] It matches any decimal digit from 0 through 9.
[a-z] It matches any character from lowercase a through lowercase z.
[A-Z] It matches any character from uppercase A through uppercase Z.
[a-Z] It matches any character from lowercase a through uppercase Z.
The ranges shown above are general; you could also use the range [0-3] to match any decimal digit ranging from 0 through 3, or the range [b-v] to match any lowercase character ranging from b through v.
Using regular expression you can search a particular string inside a another string, you can replace one string by another string and you can split a string into many chunks.
PHP offers functions specific to two sets of regular expression functions, each corresponding to a certain type of regular expression. You can use any of them based on your comfort.
POSIX Regular Expressions
PERL Style Regular Expressions
POSIX Regular Expressions:
The structure of a POSIX regular expression is not dissimilar to that of a typical arithmetic expression: various elements (operators) are combined to form more complex expressions.
The simplest regular expression is one that matches a single character, such as g, inside strings such as g, haggle, or bag.
Lets give explaination for few concepts being used in POSIX regular expression. After that we will introduce you wih regular expression related functions.
Brackets
Brackets ([]) have a special meaning when used in the context of regular expressions. They are used to find a range of characters.
Expression Description
[0-9] It matches any decimal digit from 0 through 9.
[a-z] It matches any character from lowercase a through lowercase z.
[A-Z] It matches any character from uppercase A through uppercase Z.
[a-Z] It matches any character from lowercase a through uppercase Z.
The ranges shown above are general; you could also use the range [0-3] to match any decimal digit ranging from 0 through 3, or the range [b-v] to match any lowercase character ranging from b through v.
asianmartt
New member
Regular expressions are nothing more than a sequence or pattern of characters itself. They provide the foundation for pattern-matching functionality.
PHP offers functions specific to two sets of regular expression functions, each corresponding to a certain type of regular expression. You can use any of them based on your comfort.
POSIX Regular Expressions
PERL Style Regular Expressions
PHP offers functions specific to two sets of regular expression functions, each corresponding to a certain type of regular expression. You can use any of them based on your comfort.
POSIX Regular Expressions
PERL Style Regular Expressions