`strtoupper()` Make a string uppercase

Learn how to force a string value to uppercase.

strtoupper() function takes one string as an input and converts all lowercase characters of the string to uppercase.

This function only affects the alphabets and other characters remain same.

`strtoupper()` prototype

string strtoupper ( string $str )

This means that strtoupper() accepts string and returns the uppercased string (uppercased the all lowercase characters). We could rewrite the above function definition in an easy to understandable way:

**Explanation of `strtoupper()` function definition**
Function Part	Description
string	Type of value this function returns, which is a string, in this case returns the lowercased string.
strtoupper	The function name
string	Parameter type, this function accepts only string data type
$str	Parameter name, a variable that holds the data

Syntax

strtoupper($str)

Return Value

strtoupper() function returns string, with uppercased all the alphabetic characters.

Examples

Example 1

<?php
    $str = 'I am PHP string';
    //upercase entire string
    $Uppercase = strtoupper($str);
    echo $Uppercase;
?>

The above code prints I AM PHP STRING on browser screen.

strtoupper() Make a string uppercase

strtoupper() prototype

Syntax

Return Value

Examples

Contents and Related Tutorials

`strtoupper()` Make a string uppercase

`strtoupper()` prototype