Use Of Expressions By A Php Developer In India For Php Development

By Author: janie philip
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Modifying and examining text is crucial to ensure that the PHP application so developed by the PHP developer in India works perfectly. Doing it manually is a tedious and time consuming process. Regular expressions often referred to as a mini programming language ease the task by allowing PHP developer to parse and describe text; search patterns within a string as well as extract matches flexibly and precisely. While they are very powerful, there power is also their drawback as it reduces their speed. Hence a PHP developer in India prefers to use them in case of unavoidable situations while working on a project for PHP development.

The next question posing here would be exactly how does a PHP developer in India uses regular expressions for PHP development. Developer does not have to do anything special as PHP itself provides functions for using regular expressions. Functions include replacing patterns, matching patterns and array processing using two different varieties of them like POSIX extended and Perl-Compatible Regular Expressions (PCRE). Latter functions are more powerful and faster than the former ones.

To ...
... understand how PHP functions work it is important to know the basics of regular expressions used by a PHP developer. Most characters in an expression match only themselves. For example if you want to search for foo in the string we are playing football it will find matching results because foo is there in football. Special characters used in PHP development have special meaning.

Here are a few examples of it:

1) $ is useful for matching strings that end with the given pattern

2) (^) is used at the beginning of a regular expression and should always match the string beginning

3) (.) is a metacharacter and matches every character except newline (\)

4) (|) is used as an option in regular expression

The best part of PHP is it gives PHP developer freedom to work on as required basis. While designing pattern a PHP developer in India can either build character class to specify a set of acceptable characters or use a predefined class. Bunch of characters can be represented as a single item in a regular expression using a character class.

If a PHP developer wants to create own character class it can be done by using square brackets and enclosing the acceptable characters in it. To define limits of a character class simply put first and last characters and separate them using a hyphen. It also allows you to create negated character class which matches any character that is not in the class.

Characters used in PHP development are classified in two different classes called literals (those which match themselves) and metacharacters (characters with special meanings). Metacharacter define the way in which the character should be matched like:

1) *would mean match zero or more of the preceding expression

2) + would mean match one or more of the preceding expression

3) ? would mean match zero or one of the preceding expression

Curly brackets are used distinctly and the integer included in them defines their function. {n} would mean match exactly n occurrences of the preceding expression; {n,} would mean match n or more occurrences of the preceding expression and {n,m} would mean match the previous character if it occurs at least n times, but no more than m times.

eTatvasoft a company aggressively involved in promoting PHP development has a team of expert PHP developer in India with the right attitude towards it.