How can regular expressions (Regex) be utilized in PHP to validate input variables and ensure they meet specific criteria, such as being 2-3 digit numbers?

Regular expressions in PHP can be utilized to validate input variables by defining specific patterns that the input must match. To ensure that an input variable is a 2-3 digit number, a regular expression pattern can be created to match numbers between 10 and 999. This pattern can then be used with the preg_match function to check if the input variable meets the criteria. 

$input = "123"; // Input variable to validate

if (preg_match('/^\d{2,3}$/', $input)) {
    echo "Input is a 2-3 digit number.";
} else {
    echo "Input is not a 2-3 digit number.";
}

Keywords

PHP Regular Expressions Regex Validation Input Variables

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