使用preg_match验证字符串格式

问题描述：

I have an html form with an input for a sales order number which should have the format of K1234/5678. It should always start with the letter K then 4 numbers, a / and followed by another set of 4 numbers.

I'm trying to validate the formatting using preg_match and I'm getting lost in the syntax of preg_match. From http://php.net/manual/en/function.preg-match.php I've gotten close. With the following code I'm able to verify that it contains at least 1 letter, some numbers and at least 1 non- alphanumeric value.

$so= $_POST['so'];
if (preg_match(""/^(?=.*[a-z]{1})(?=.*[0-9]{4})(?=.*[^a-z0-9]{1})/i", $so))
{
    print $so;
}

What is the correct syntax to use for this? Is preg_match even the best way to do this?

我有一个html表单，其中包含一个销售订单号的输入，其格式应为K1234 / 5678。它应始终以字母K开头，然后是4个数字，a /后跟另一组4个数字。 p>

我正在尝试使用preg_match验证格式，我在preg_match的语法中迷路了。来自 http://php.net/manual/en/function.preg-match。 php 我已经接近了。使用以下代码，我能够验证它包含至少1个字母，一些数字和至少1个非字母数字值。 p>

  $ so = $ _POST ['so']; 
if（preg_match（“”/ ^（？=。* [az] {1}）（？=。  * [0-9] {4}）（？=。* [^ a-z0-9] {1}）/ i“，$ so））
 {
 print $ so; 
} 
   pre> 
 
 用于此的正确语法是什么？preg_match甚至是最好的方法吗？ p> 
  div>

答

Try this:

preg_match("#^K[0-9]{4}/[0-9]{4}$#i", $so)

Explanation:

The # characters are regular expression delimiters - they indicate the start/end of the pattern. The ^ and $ indicate the start and end of the string - this means that it will only match if your sales order number is the only thing in the string. The letter K means match that letter, [0-9]{4} means match a digit exactly 4 times. The i at the end means a case-insensitive match - the K will match either "K" or "k".

When developing regular expressions, I often use regular expression testers - these allow you to enter your data and try a bunch of different things to refine your regex. Google PHP regex tester to find a list of tools. Also, there's a very complete reference to regular expressions at http://www.regular-expressions.info/.

使用preg_match验证字符串格式

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