PHP sscanf() Function

What is PHP sscanf() Function?

If you want to parse (analyze and convert) inputs from a string into variables based on a specified format, use sscanf() function.

Syntax:

sscanf(string, format, variable1, variable2,…)

Parameters:

The Function has 2 required parameter2 and any number of optional parameters-

string (Required): It specifies the input string.

format (Required): It specifies the pattern to use for formatting the input string. For formatting, the follows the rules that are described in sprint() function, except the followings-

  • Function is not locale-aware.
  • F, g, G and b are not supported.
  • D stands for decimal number.
  • i stands for integer with base detection.
  • n stands for number of characters processed so far.
  • s stops reading at any whitespace character.
  • instead of argnum$ suppresses the assignment of this conversion specification.

variable1, variable2,… (Optional): It specifies one or more variables that holds the parsed values.

Return Values:

The return value depends on whether or not the optional variables are used-

  • When no optional variables are used: The function returns an array containing all the parsed values.
  • When optional variables are used: The function stores the parsed values in those variables and returns those.
    • The function returns NULL if there are more formatting rules in the format parameter than available substrings in the input string.

Practical Usages of sscanf() Function:

Here are some practical usages of sscanf() function-

  1. Converting color codes from Hexadecimal to its equivalent RGB code using %x or %X format specifier- 
    <?php
$Hex_code = 'FF0000';
list($r, $g, $b) = sscanf($Hex_code, '%2x%2x%2x');
echo "RGB color code of Hexadecimal code \"FF0000\" is: $r, $g, $b";
?>

    Output:

    RGB color code of Hexadecimal code "FF0000" is: 255, 0, 0

  2. Extracting data from log file- 
    <?php
$log = "2025-12-29 17:30:05 INFO: User logged in";
list($year, $month, $day) = sscanf($log, "%d-%d-%d");
echo "User's logged in date was: " . $month . "/" . $day . "/" . $year;
?>

    Output:

    User's logged in date was: 12/29/2025

  3. Extracting product no. from product code- 
    &lt;?php
$product_code = "CRN/5117";
sscanf($product_code, "CRN/%d", $serial_no);
echo "Serial number of the product code ". $product_code . "is: " . $serial_no;
?>

    Output:

    Serial number of the product code CRN/5117is: 5117

  4. Parsing from specific delimiter- 
    <?php
$string = "ID: 1, Name: John";
list($id, $name) = sscanf($string, "ID: %d, Name: %s, Sex: %s");
echo "Person name: ". $name . " and his id is: " . $id;
?>

    Output:

    Person name: John and his id is: 1
  5. For parsing a string that has fixed patterns, sscanf() is usually faster than preg_match() function.

PHP Version Support:

PHP 4 >= 4.0.1, PHP 5, PHP 7, PHP 8

Summary: PHP sscanf() Function

The sscanf() function is a built-in PHP function and part of the PHP’s string functions. Use this function to extract information from structural data.

Reference:

https://www.php.net/manual/en/function.sscanf.php