PHP Tutorial: How to handle php substrings

Introduction

In this PHP tutorial, I'll show you different methods that can be used for handling substring of strings in PHP. PHP have already some inbuilt functions by which you can handle such tasks. This functions allows programmers to fetch/retrieve and modify specific portion of any string (i.e. An Array of Characters) in a simple and easier way. You can split strings into chunks too via using this PHP functions.

How to handle PHP substrings?
How to handle PHP substrings?

List of Functions I'm Talking About

In this Section, I'm publishing the list of all those functions that can used to handle sub-string of Strings in PHP and You can also view my another PHP article that includes full list of String Manipulating functions in PHP.

  1. PHP substr() function - Return part of a string.

  2. PHP strpos() function - Returns the position of first occurrence of needle (substring) in haystack (bigger string).
  3. PHP substr_count() function - Counts the number of substring occurrences inside haystack.
  4. PHP strrpos() function - Returns the position of last occurrence of needle in haystack.
  5. PHP explode() function - Returns an array of strings, each of which is a substring of string formed by splitting it on boundaries formed by the string delimiter.
  6. PHP substr_compare() function - Binary safe comparison of two strings from an offset (Start Position), up to length characters.
  7. PHP str_split() function - Converts a string to an array. If the optional split_length parameter is specified, the returned array will be broken down into chunks with each being split_length in length, otherwise each chunk will be one character in length.
  8. PHP stristr() function - Returns all of haystack from the first occurrence of needle to the end.
  9. PHP strtr() function - Translate characters or replace substrings.
  10. PHP str_word_count() function - Return information about words used in a string.
  11. PHP substr_replace() function - Replace text within a portion of a string.
  12. PHP str_replace() function - Replace all occurrences of the search string with the replacement string.

Out of those listed above, we'll focus on three main functions i.e. substr(), explode() and substr_replace() of PHP. Here, below is the syntax of each of this functions and to learn more about PHP function syntax, you are free to visit the link.

Syntax of PHP substr(), explode() and substr_replace() functions

//Here, Below is the syntax of PHP substr() function
string substr ( string $string , int $start [, int $length ] );

//And, Here is the syntax of PHP explode function
array explode ( string $delimiter , string $string [, int $limit ] );

//And, below is syntax of PHP substr_replace() function
mixed substr_replace ( mixed $string , mixed $replacement , mixed $start [, mixed $length ] );

Here, below is the example showing usage of this functions and output generated by them.

PHP Code Showing Usage of substr(), explode() and substr_replace() Function of PHP

<?php
//Examples Showing Usage of substr() function, 
//outputs are printed on right side of PHP statements...
//...in the form of comments

echo substr('abcdef', 1);     // bcdef
echo substr('abcdef', 0, 8);  // abcdef
echo substr('abcdef', -1, 2); // ef

// Accessing single characters in a string
// can also be achieved using "square brackets"
$string = 'abcdef';
echo $string[0];                 // a
echo $string[3];                 // d
echo $string[strlen($string)-1]; // f

?> 

<?php
// Example showing the usage of explode function, output is printed on right side.

$myStatement  = "I'm not a gangster.";
$pieces = explode(" ", $myStatement);
echo $pieces[0]; // I'm
echo $pieces[1]; // not
echo $pieces[3]; // gangster.
?>

<?php
/**
**Below is the Example showing simple usage of substr_replace function
**/
$var = 'ABCDEFGH:/MNRPQR/';
echo "Original: $var<hr />\n";

/**
**These wiill replace value stored in 
**$var (i.e. whole text) with "bob"
**/
echo substr_replace($var, 'bob', 0) . "<br />\n";

//These next two replace 'MNRPQR' in $var with 'bob'.
echo substr_replace($var, 'bob', 10, -1) . "<br />\n";
echo substr_replace($var, 'bob', -7, -1) . "<br />\n";
/**
**Output of above code will be this
Original: ABCDEFGH:/MNRPQR/<hr>
bob<br>
ABCDEFGH:/bob/<br>
ABCDEFGH:/bob/<br>
**/

/**
**Below is the Example showing usage of substr_replace function
** to replace multiple strings at once
**/

$input = array('Im', 'Not a', 'Gangster');

// A simple case: replace words in each string with YYY.
print_r(substr_replace($input, 'YYY', 0));
/*
**output will be
**
Array
(
    [0] => YYY
    [1] => YYY
    [2] => YYY
)
**/

// A more complicated case where each replacement is different.
$replace = array('AAA', 'BBB', 'CCC');
print_r(substr_replace($input, $replace, 0));
/*
**output will be
**
Array
(
    [0] => AAA
    [1] => BBB
    [2] => CCC
)
**/

?>

so, that's all you need to know about substring functions of PHP. Well, it is not so hard to develop your own substring functions using for loops in PHP.

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Comments 7 comments

paxwill profile image

paxwill 5 years ago from France

I like writing math programs in PHP, but whenever I need to manipulate string variables I give up and write in another language. Guess I need to sit down and brush up on my PHP skills. Nice hub.


itech profile image

itech 5 years ago from New Delhi, India Author

@paxwill, thanks for commenting.


tnvrstar profile image

tnvrstar 5 years ago from doha, qatar

very useful Hub! I don't have much Idea about PHP but I will look forward to it.


itech profile image

itech 5 years ago from New Delhi, India Author

Hello @tnvstar, Thanks for commenting.


Rajumukherjee profile image

Rajumukherjee 5 years ago from varanasi

can you help me how to take a photo of a running application on computer for my website


itech profile image

itech 5 years ago from New Delhi, India Author

hello @rajumukherjee, Yes Sure, You can do that by pressing "print screen" button, then, paste it into paint (or similar application). after, that save it as image on your computer.


Rajumukherjee 4 years ago

Thank you since you are good at php what do you think about hosting a website and how much info is required to handle php my blog is on blogger netalien.biz so i have not dealed with it yet

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