PHP regular expression to verify whether the input string is in the correct vehicle frame number format

With the popularity and increase in the number of cars, chassis numbers have become an indispensable part of our lives. The frame number is the "ID card" of the vehicle. It is a unique coded identification that can describe the vehicle's manufacturer, year of manufacture, vehicle model and other information. Therefore, it is very important for automobile manufacturers and users to correctly identify and verify the accuracy of the frame number. In this article, we will introduce how to use PHP regular expressions to verify that the input string is in the correct vehicle frame number format.

First of all, let us understand the basic format of the frame number. The frame number usually consists of 17 characters, which can be a combination of numbers and letters. The following is the format of the frame number:

1. The 1st digit: Indicates the place of production of the vehicle, usually a number or letter;
2. The 2nd digit: Indicates the manufacturer of the vehicle, usually are letters; the 3rd to 8th digits of
3. : represent the vehicle model, usually a combination of numbers and letters; the 9th digit of
4. : represent the check digit, which is used to verify the entire frame number Whether the digits are in the correct format, usually numbers or letters;
5. digits 10 to 17: Indicates the production serial number of the vehicle, usually a combination of numbers and letters.

According to the format of the frame number, we can use PHP regular expressions for verification. The following is a sample code:

function validateVin($vin) {
  $pattern = '/^[A-HJ-NPR-Z0-9]{17}$/';
  return preg_match($pattern, strtoupper($vin));
}

// 示例使用
$vin = '1GKFK63119R178558';
if (validateVin($vin)) {
  echo '车架号为正确格式';
} else {
  echo '车架号为错误格式';
}

In the above code, we use PHP's preg_match function to match regular expressions. This function will return a number indicating whether the string matches the regular expression successfully. If the match is successful, 1 is returned, otherwise 0 is returned.

Some key points of regular expressions:

1. ^ represents the starting position of the string;
2. $ represents the ending position of the string;
3. [] means to match any character within the square brackets;
4. {17} means to match the previous character appearing exactly 17 times.

Finally, we need to note that the check digit of the frame number is calculated according to the ISO 3779 standard and is not set arbitrarily. Therefore, when actually verifying the frame number, we need to perform calculations according to the ISO 3779 standard to ensure the accuracy of the verification.

In short, it is very simple to use PHP regular expressions to verify whether the input string is in the correct frame number format. Just use regular expressions for matching and perform verification according to the ISO 3779 standard. The correct frame number format can help us better understand the vehicle's information, and can also prevent traffic accidents and other problems caused by incorrect frame numbers.

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