PHP strrchr() for Finding the Last Occurrence in Strings

1. What is strrchr()?

The PHP strrchr() function is used to find the last occurrence of a character in a string and returns the part of the string from that character onwards.
Syntax:

strrchr(string $haystack, string $needle): string|false

- $haystack: The input string to search within.
- $needle: The character to search for.
- Return Value: It returns the portion of the string starting from the last occurrence of the needle (including the needle itself). If the needle is not found, it returns `false`.

2. Example 1: Basic Usage

The example below demonstrates how to find the last occurrence of a character in a string:

$text = "Hello world, welcome to PHP";
$result = strrchr($text, 'o');
echo $result;

Output:

o PHP

Here, the last occurrence of the character "o" is found, and the rest of the string from that point is returned.

3. Example 2: Searching for a Substring

Although strrchr() is commonly used to find characters, it can also be used to locate substrings:

$text = "Welcome to the plus2net.com programming world";
$result = strrchr($text, ".com");
echo $result;

Output:

.com programming world

4. Example 3: Handling Non-existent Characters

If the character is not found in the string, strrchr() will return `false`:

$text = "Welcome to PHP";
$result = strrchr($text, 'x');
var_dump($result);

Output:

bool(false)

5. Example 4: Extracting File Extensions

The strrchr() function is particularly useful when extracting file extensions from filenames:

$filename = "document.pdf";
$extension = strrchr($filename, '.');
echo $extension;

Output:

.pdf

This example shows how to get the file extension by searching for the last occurrence of the period . character.

6. Case Sensitivity

strrchr() is case-sensitive, meaning that searching for a lowercase character will not match its uppercase equivalent. Here's an example:

$text = "HELLO World!";
$result = strrchr($text, 'O');
echo $result;

Output:

O World!

Searching for 'O' (uppercase) would not match with lowercase o inside World since it is case-sensitive.

7. Comparing strrchr() and strchr()

While strrchr() finds the last occurrence of a character, strchr() (or its alias strstr()) finds the first occurrence of a character. Here’s a comparison: Using strrchr():

$text = "Hello world, welcome to PHP";
$result = strrchr($text, 'o');
echo $result; // Output: "o PHP"

Using strchr():

$result = strchr($text, 'o');
echo $result; // Output: "o world, welcome to PHP"

8. Best Practices for strrchr()

- Extracting File Extensions:
Use strrchr() to easily get file extensions from filenames.
- String Parsing: When working with log files, URLs, or file paths, strrchr() can be used to extract relevant information, such as the last directory or domain name.

Conclusion

The strrchr() function is a powerful and useful PHP string function for locating the last occurrence of a character in a string. It is ideal for tasks like parsing file paths, URLs, or extracting extensions.
String Functions Next: strrev() - Reversing a String chunk_split(): Split a string into smaller chunks

Subhendu Mohapatra

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Passionate about coding and teaching, I publish practical tutorials on PHP, Python, JavaScript, SQL, and web development. My goal is to make learning simple, engaging, and project‑oriented with real examples and source code.