PHP - Strings

Single-quote strings

This type of strings does not processes special characters inside quotes.

 <?php 
$x  = 'Code Always'; 
echo $x; 
 ?>

Single-quotes strings in PHP does not processes special characters.

Double-quote strings

Unlike single-quote strings, double-quote strings in PHP is capable of processing special characters.

  <?php 
$x  = 'Code Always'; 
echo $x; 
echo "Welcome to $x"; 
 ?>  

In PHP the character beginning with a backslash(“\”) are treated as escape sequences and are replaced with special characters. Here are few important escape sequences.

 <?php 
 $x  = 'Code Always.'; 
 echo $x; 
 echo "Welcome to $x \n"; 
 echo "$x "; 
 ?>

 Welcome to Code Always.
 Code Always.   

Built-In String Functions

Built-in functions in PHP are some existing library functions which can be used directly in our programs making an appropriate call to them

strlen() function

The PHP strlen() function returns the length of a string.

 <?php 
 echo strlen("Code Always."); 
 ?>

The output of the above PHP code is '12'.

strrev() function

The PHP strrev() function reverses a string.

 <?php 
 echo strrev("Code Always."); 
 ?> 

The output of the above PHP code is '.syawlA edoC'.

strpos() function

The PHP strpos() function searches for a specific text within a string.

 <?php 
 echo strpos("Code Always.","Always"); 
 ?>

The output of the above PHP code is '6'.

str_replace()() function

The PHP str_replace() function replaces some characters with some other characters in a string.

 <?php 
 echo str_replace("Now","Always","Code Now."); 
 ?>

The output of the above PHP code is 'Code Always.'.

NOTE - Built-in string functions is given in function reference PHP String Functions