How to case strings in PHP

In PHP, you can use: strtoupper() function, strtolower() function, ucfirst() function, lcfirst() function to case strings. The following article will give you a detailed introduction, I hope it will be helpful to you.

strtoupper() function

strtoupper() function can take a string as a parameter, and then The string is converted to all uppercase and returned.

Basic syntax:

strtoupper(string)

Example:

<?php 
function toUpper($string){ 
    return(strtoupper($string)); 
} 
$string="Hello world!";   
echo (toUpper($string)); 
?>

Output:

##strtolower( )Function

strtolower(string)

<?php 
function toUpper($string){ 
    return(strtolower($string)); 
} 
$string="JAVASCRIPT";   
echo (toUpper($string)); 
?>

##ucfirst( )Function ucfirst() function can take a string as a parameter, and then convert the first letter of the string to uppercase, leaving other characters unchanged, and return.

Basic syntax:

ucfirst(string)

Example:

<?php 
function toUpper($string){ 
    return(ucfirst($string)); 
} 
$string="hello world!";   
echo (toUpper($string)); 
?>

Output:

lcfirst() function can take a string as a parameter, and then convert the first letter of the string to lowercase, leaving the other characters unchanged, and return it.

lcfirst(string)

<?php 
function toUpper($string){ 
    return(lcfirst($string)); 
} 
$string="PHP中文网！";   
echo (toUpper($string)); 
?>

The above is the entire content of this article , I hope it can be helpful to everyone’s study. For more exciting content, you can pay attention to the relevant tutorial columns of the PHP Chinese website! ! !

The above is the detailed content of How to case strings in PHP. For more information, please follow other related articles on the PHP Chinese website!