Changing Case

PHP has four everyday functions for changing the case of text.

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<?php
$text = "hello wORLD";

echo strtoupper($text) . "\n";
echo strtolower($text) . "\n";
echo ucfirst($text) . "\n";
echo ucwords($text);

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HELLO WORLD
hello world
Hello wORLD
Hello WORLD

ucfirst() and ucwords() do not lower the other letters. To normalise text, lower it first.

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<?php
$name = "aNiL kUMAR";

echo ucwords(strtolower($name));

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Anil Kumar

Compare text without caring about case

Lower both sides before comparing.

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<?php
$typed = "YES";

if (strtolower($typed) === "yes") {
    echo "Confirmed";
}

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Confirmed

Lowercase an email

Email addresses are usually compared in lowercase.

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<?php
$email = " Ravi@Example.COM ";

echo strtolower(trim($email));

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ravi@example.com

Names have exceptions

ucwords() is great for simple cases, but names like “McDonald” or “van der Berg” will be changed incorrectly. Do not force the case of real names. Accept what the user typed.

Text with accents

The plain functions work on English letters. For other alphabets, use the mb_ versions.

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<?php
echo mb_strtoupper("zoë café");

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ZOË CAFÉ

In PHP 8.4 there are also mb_ucfirst() and mb_lcfirst().