How can PHP be used to validate a form field where a minimum of 2 letters must be entered?

To validate a form field where a minimum of 2 letters must be entered, you can use PHP to check the length of the input string and ensure that it contains at least 2 letters. This can be done by using the strlen() function to get the length of the input and then using a regular expression to match at least 2 letters. If the validation fails, you can display an error message to the user. 

$input = $_POST['field_name'];

if (strlen($input) < 2 || !preg_match('/[a-zA-Z].*[a-zA-Z]/', $input)) {
    echo "Please enter at least 2 letters.";
} else {
    // Form field is valid
}

Keywords

PHP form validation input validation strlen() error handling

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