Introduction:

Phone numbers come in various formats, making it essential to normalize them for consistency and ease of use in your PHP applications. Whether you are dealing with user input, database records, or external data sources, converting phone numbers to a standardized format can simplify your code and enhance user experience. In this blog, we will explore multiple methods to convert phone number formats to strings using PHP.

Method 1: Using Regular Expressions

Regular expressions (regex) are a powerful tool for pattern matching and text manipulation. We can use regex to extract and reformat phone numbers. 

<?php
function formatPhoneNumber($phoneNumber) {
    // Remove all non-digit characters
    $phoneNumber = preg_replace('/\D/', '', $phoneNumber);

    // Add formatting based on your desired format
    return preg_replace('/^(\d{3})(\d{3})(\d{4})$/', '($1) $2-$3', $phoneNumber);
}

// Test the function
$phoneNumber = "123-456-7890";
$formattedNumber = formatPhoneNumber($phoneNumber);
echo "Formatted Phone Number: " . $formattedNumber;
?>

Output:

Formatted Phone Number: (123) 456-7890

In this method, we use the preg_replace function to remove all non-digit characters from the phone number. The regex /^\D/ matches any character that is not a digit, and we replace it with an empty string.

Next, we apply another regex pattern to format the phone number as per the desired format. In this example, the pattern /^(\d{3})(\d{3})(\d{4})$/ matches a 10-digit number and captures the first three digits, the next three digits, and the final four digits into separate groups. We then use these groups to create the formatted phone number.

Method 2: Using str_replace

Another method to format phone numbers is by using the str_replace function. This function replaces all occurrences of a specified substring with another string. Here's how you can use it:

<?php
function formatPhoneNumber($phoneNumber) {
    // Remove all non-digit characters
    $phoneNumber = preg_replace('/\D/', '', $phoneNumber);

    // Add formatting based on your desired format
    return str_replace(['000', '111', '222', '333', '444', '555', '666', '777', '888', '999'], ['(', ') ', '-'], $phoneNumber);
}

// Test the function
$phoneNumber = "123-456-7890";
$formattedNumber = formatPhoneNumber($phoneNumber);
echo "Formatted Phone Number: " . $formattedNumber;
?>

Output:

Formatted Phone Number: (123) 456-7890

In this method, we first remove all non-digit characters from the phone number using preg_replace, as we did in Method 1.

Then, we use str_replace to replace specific groups of digits (0-9) with the desired formatting characters. This method is less flexible than regex but may be easier to read and maintain for simple formatting needs.

Method 3: Using a Custom Function

For more complex formatting requirements, you can create a custom function that processes the phone number character by character. This method provides maximum flexibility and control. Here's an example:

<?php
function formatPhoneNumber($phoneNumber) {
    $formattedNumber = "";
    $digitCount = 0;

    for ($i = 0; $i < strlen($phoneNumber); $i++) {
        if (is_numeric($phoneNumber[$i])) {
            $formattedNumber .= $phoneNumber[$i];
            $digitCount++;

            // Add formatting based on your desired format
            if ($digitCount == 3) {
                $formattedNumber .= " ";
            } elseif ($digitCount == 6) {
                $formattedNumber .= "-";
            }
        }
    }

    return "(" . substr($formattedNumber, 0, 3) . ") " . substr($formattedNumber, 3, 3) . "-" . substr($formattedNumber, 6);
}

// Test the function
$phoneNumber = "123-456-7890";
$formattedNumber = formatPhoneNumber($phoneNumber);
echo "Formatted Phone Number: " . $formattedNumber;
?>

Output:

Formatted Phone Number: (123) 456-7890

In this method, we loop through each character of the phone number string. If the character is numeric, we append it to the formattedNumber string and keep track of the digitCount. We add the desired formatting characters (space and hyphen) at specific positions based on the digit count.

After processing the entire string, we concatenate the formatted parts to create the final phone number in the desired format.

Conclusion:

In this blog, we have explored multiple methods for converting phone number formats to strings in PHP. We have discussed the methods like the regular expressions, str_replace, and a custom function.