Explain some of the PHP string functions?

PHP String Function Examples

1) PHP strtolower() function

The strtolower() function returns string in lowercase letter.

Syntax

string strtolower ( string $string )

Example

<?php  
$str="My name is KHAN";  
$str=strtolower($str);  
echo $str;  
?>

Output:

my name is khan

2) PHP strtoupper() function

The strtoupper() function returns string in uppercase letter.

Syntax

string strtoupper ( string $string )

Example

<?php  
$str="My name is KHAN";  
$str=strtoupper($str);  
echo $str;  
?>

Output:

MY NAME IS KHAN

3) PHP ucfirst() function

The ucfirst() function returns string converting first character into uppercase. It doesn't change the case of other characters.

Syntax

string ucfirst ( string $str )

Example

<?php  
$str="my name is KHAN";  
$str=ucfirst($str);  
echo $str;  
?>

Output:

My name is KHAN

4) PHP lcfirst() function

The lcfirst() function returns string converting first character into lowercase. It doesn't change the case of other characters.

Syntax

string lcfirst ( string $str )

Example

<?php  
$str="MY name IS KHAN";  
$str=lcfirst($str);  
echo $str;  
?>

Output:

mY name IS KHAN

5) PHP ucwords() function

The ucwords() function returns string converting first character of each word into uppercase.

Syntax

string ucwords ( string $str )

Example

<?php  
$str="my name is Sonoo jaiswal";  
$str=ucwords($str);  
echo $str;  
?>

Output:

My Name Is Sonoo Jaiswal

6) PHP strrev() function

The strrev() function returns reversed string.

Syntax

string strrev ( string $string )

Example

<?php
$str="my name is Sonoo jaiswal";
$str=strrev($str);
echo $str;
?>

Output:

lawsiaj oonoS si eman ym

7) PHP strlen() function

The strlen() function returns length of the string.

Syntax

int strlen ( string $string )

Example

<?php  
$str="my name is Sonoo jaiswal";  
$str=strlen($str);  
echo $str;  
?>

Output: