Method to verify QQ number using PHP regular expression

In PHP development, it is often necessary to verify and format the data input by the user. Especially for common data such as QQ numbers, the verification of its format is particularly important. So how to use PHP regular expressions to verify QQ numbers? This article will introduce the specific implementation method, hoping to be helpful to PHP developers and beginners.

QQ number format rules:

• QQ number is composed of 5-13 digits.
• The first digit cannot be 0.
• QQ numbers do not have leading 0s.

In view of the format rules of QQ numbers, we can use regular expressions for verification. The specific implementation method is as follows:

1. Use the preg_match() function to verify
   We can use the preg_match() function and regular expressions to determine whether the entered QQ number meets the rules. The following is a code example:

function checkQQ($qq) {
  if (preg_match('/^[1-9][0-9]{4,12}$/', $qq)) {
    return true;
  }
  return false;
}

Explain the above code:

• preg_match() function is used to match regular expressions.
• '/^1-9{4,12}$/' is a regular expression, which means starting with any number from 1 to 9, followed by 4 to 12 numbers, $ represents a regular expression The end of the formula.
• If the incoming $qq conforms to the regular expression rules, return true, otherwise return false.

2. Use filter_var() function for verification
   In addition to using the preg_match() function for verification, we can also use the filter_var() function provided by PHP for verification. The following is a code example:

function checkQQ($qq) {
  if (filter_var($qq, FILTER_VALIDATE_INT, array('options' => array('min_range'=>10000, 'max_range'=>9999999999999)))) {
    return true;
  }
  return false;
}

Explain the above code:

• filter_var() function is used to verify the validity of the data.
• FILTER_VALIDATE_INT indicates integer verification of $qq.
• 'options' => array('min_range'=>10000, 'max_range'=>9999999999999) means to limit the value range of $qq, between 10000 and 9999999999999.
• If the incoming $qq meets the restriction range, return true, otherwise return false.

Both of the above two methods can verify whether the format of the QQ number is correct. Using regular expressions for verification can be more flexible and meet the needs of different scenarios. At the same time, paying attention to input validation during development is a very important security measure that can prevent many common security vulnerabilities. I hope this article will be helpful to everyone, and I also hope that everyone will practice frequently during the learning process and continuously improve their practical development skills.

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