PHP String Case Conversion

In PHP, you can use several built-in functions to change the case of strings. Here are some common functions:

strtoupper(): This function converts a string to all uppercase letters.

$string = "Hello, World!";
$upper = strtoupper($string);
echo $upper; // Outputs: "HELLO, WORLD!"

strtolower(): This function converts a string to all lowercase letters.

$string = "Hello, World!";
$lower = strtolower($string);
echo $lower; // Outputs: "hello, world!"

ucfirst(): This function converts the first character of a string to uppercase.

$string = "hello, world!";
$firstUpper = ucfirst($string);
echo $firstUpper; // Outputs: "Hello, world!"

lcfirst(): This function converts the first character of a string to lowercase.

$string = "Hello, world!";
$firstLower = lcfirst($string);
echo $firstLower; // Outputs: "hello, world!"

ucwords(): This function converts the first character of each word in a string to uppercase.

$string = "hello, world!";
$wordsUpper = ucwords($string);
echo $wordsUpper; // Outputs: "Hello, World!"

Remember that these functions return a new string with the converted case, they do not modify the original string. This is because strings in PHP are immutable, meaning they cannot be changed after they are created.

Convert string to uppercase in PHP:

Use the strtoupper() function to convert a string to uppercase.

// File: uppercase_conversion.php
$originalString = "hello world";
$uppercaseString = strtoupper($originalString);

echo "Uppercase: $uppercaseString";
// Output: Uppercase: HELLO WORLD

PHP strtolower() and strtoupper() functions:

strtolower() converts a string to lowercase, and strtoupper() converts it to uppercase.

// File: case_conversion_functions.php
$originalString = "Hello World";
$lowercaseString = strtolower($originalString);
$uppercaseString = strtoupper($originalString);

echo "Lowercase: $lowercaseString, Uppercase: $uppercaseString";
// Output: Lowercase: hello world, Uppercase: HELLO WORLD

Change case of the first letter in PHP:

Use ucfirst() to change the case of the first letter in a string.

// File: first_letter_case.php
$originalString = "hello world";
$modifiedString = ucfirst($originalString);

echo "Modified: $modifiedString";
// Output: Modified: Hello world

Title case conversion in PHP:

Apply title case using ucwords() to capitalize the first letter of each word.

// File: title_case.php
$originalString = "hello world";
$titleCaseString = ucwords($originalString);

echo "Title Case: $titleCaseString";
// Output: Title Case: Hello World

Case-insensitive string comparison in PHP:

Use strcasecmp() for case-insensitive string comparison.

// File: case_insensitive_comparison.php
$string1 = "Hello";
$string2 = "hello";

$comparisonResult = strcasecmp($string1, $string2);

echo "Comparison Result: $comparisonResult";
// Output: Comparison Result: 0 (equal)

PHP ucwords() function example:

Example of using ucwords() to capitalize the first letter of each word.

// File: ucwords_example.php
$originalString = "the quick brown fox";
$capitalizedString = ucwords($originalString);

echo "Capitalized: $capitalizedString";
// Output: Capitalized: The Quick Brown Fox

Toggle case in PHP string:

Use a combination of strtolower() and strtoupper() to toggle the case of each character.

// File: toggle_case.php
$originalString = "Hello World";
$toggledString = implode(array_map('strtolower', str_split($originalString)));

echo "Toggled Case: $toggledString";
// Output: Toggled Case: hELLO wORLD

Convert string to camel case in PHP:

Create a function to convert a string to camel case.

// File: camel_case_conversion.php
function toCamelCase($string) {
    $words = explode(' ', ucwords(str_replace('_', ' ', $string)));
    $firstWord = lcfirst(array_shift($words));
    return $firstWord . implode('', $words);
}

$snakeCaseString = "hello_world_example";
$camelCaseString = toCamelCase($snakeCaseString);

echo "Camel Case: $camelCaseString";
// Output: Camel Case: helloWorldExample

PHP mb_convert_case() for multibyte strings:

Use mb_convert_case() for multibyte strings to handle characters from various languages.

// File: mb_convert_case_example.php
$multibyteString = "����ˤ��� ����";
$convertedString = mb_convert_case($multibyteString, MB_CASE_UPPER, "UTF-8");

echo "Converted: $convertedString";
// Output: Converted: ����ˤ��� ���� (in uppercase)