String Length and Case
Measure a string with strlen() and change its case with the case functions.
Syntax
strlen($string);PHP has many built-in string functions. Some of the most common:
strlen()— returns the number of characters.strtoupper()— converts to uppercase.strtolower()— converts to lowercase.ucfirst()— uppercases the first character.str_word_count()— counts the words.
Example
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Press Run to execute the code.
When to use it
- Validate that a password is at least 8 characters long before saving it.
- Truncate a blog post excerpt to 150 characters and add an ellipsis.
- Convert user input to uppercase for a case-insensitive username comparison.
More examples
Measuring string length
strlen() returns the byte count of a string, making it ideal for minimum-length validation.
<?php
$password = 'secret123';
if (strlen($password) < 8) {
echo 'Password too short.';
} else {
echo 'Password length OK: ' . strlen($password);
}Changing string case
strtolower(), strtoupper(), and ucwords() normalise string case for comparisons and display.
<?php
$input = 'hello WORLD';
echo strtolower($input); // hello world
echo strtoupper($input); // HELLO WORLD
echo ucwords($input); // Hello WorldTrimming and padding strings
trim() strips whitespace from both ends; str_pad() is useful for fixed-width output like order IDs.
<?php
$raw = " hello ";
echo trim($raw); // 'hello'
echo ltrim($raw); // 'hello '
echo str_pad('42', 5, '0', STR_PAD_LEFT); // 00042
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