根据皇家邮政的程序员指南，检查邮政编码是否为有效格式:

          |----------------------------outward code------------------------------| |------inward code-----|
#special↓       α1        α2    AAN  AANA      AANN      AN    ANN    ANA (α3)        N         AA
^(GIR 0AA|[A-PR-UWYZ]([A-HK-Y]([0-9][A-Z]?|[1-9][0-9])|[1-9]([0-9]|[A-HJKPSTUW])?) [0-9][ABD-HJLNP-UW-Z]{2})$

uk上的所有邮编都匹配，除了那些不再使用的邮编。

增加一个?空格后，使用不区分大小写的匹配来回答这个问题:

'se50eg'.match(/^(GIR 0AA|[A-PR-UWYZ]([A-HK-Y]([0-9][A-Z]?|[1-9][0-9])|[1-9]([0-9]|[A-HJKPSTUW])?) ?[0-9][ABD-HJLNP-UW-Z]{2})$/ig);
Array [ "se50eg" ]

以下是我们处理英国邮政编码问题的方法:

^([A-Za-z]{1,2}[0-9]{1,2}[A-Za-z]?[ ]?)([0-9]{1}[A-Za-z]{2})$

解释:

期望有1或2个a-z字符，上或下都没问题 预期有1到2个数字 期望0或1个a-z字符，上或下精细 允许使用可选空间 期望1个数字 期望有2个a-z，上下都没问题

这将获得大多数格式，然后我们使用db来验证邮政编码是否真实，该数据由openpoint https://www.ordnancesurvey.co.uk/opendatadownload/products.html驱动

希望这能有所帮助

我需要一个可以在SAS中使用PRXMATCH和相关函数的版本，所以我想到了这个:

^[A-PR-UWYZ](([A-HK-Y]?\d\d?)|(\d[A-HJKPSTUW])|([A-HK-Y]\d[ABEHMNPRV-Y]))\s?\d[ABD-HJLNP-UW-Z]{2}$

测试用例和注意事项:

/* 
Notes
The letters QVX are not used in the 1st position.
The letters IJZ are not used in the second position.
The only letters to appear in the third position are ABCDEFGHJKPSTUW when the structure starts with A9A.
The only letters to appear in the fourth position are ABEHMNPRVWXY when the structure starts with AA9A.
The final two letters do not use the letters CIKMOV, so as not to resemble digits or each other when hand-written.
*/

/*
    Bits and pieces
    1st position (any):         [A-PR-UWYZ]         
    2nd position (if letter):   [A-HK-Y]
    3rd position (A1A format):  [A-HJKPSTUW]
    4th position (AA1A format): [ABEHMNPRV-Y]
    Last 2 positions:           [ABD-HJLNP-UW-Z]    
*/


data example;
infile cards truncover;
input valid 1. postcode &$10. Notes &$100.;
flag = prxmatch('/^[A-PR-UWYZ](([A-HK-Y]?\d\d?)|(\d[A-HJKPSTUW])|([A-HK-Y]\d[ABEHMNPRV-Y]))\s?\d[ABD-HJLNP-UW-Z]{2}$/',strip(postcode));
cards;
1  EC1A 1BB  Special case 1
1  W1A 0AX   Special case 2
1  M1 1AE    Standard format
1  B33 8TH   Standard format
1  CR2 6XH   Standard format
1  DN55 1PT  Standard format
0  QN55 1PT  Bad letter in 1st position
0  DI55 1PT  Bad letter in 2nd position
0  W1Z 0AX   Bad letter in 3rd position
0  EC1Z 1BB  Bad letter in 4th position
0  DN55 1CT  Bad letter in 2nd group
0  A11A 1AA  Invalid digits in 1st group
0  AA11A 1AA  1st group too long
0  AA11 1AAA  2nd group too long
0  AA11 1AAA  2nd group too long
0  AAA 1AA   No digit in 1st group
0  AA 1AA    No digit in 1st group
0  A 1AA     No digit in 1st group
0  1A 1AA    Missing letter in 1st group
0  1 1AA     Missing letter in 1st group
0  11 1AA    Missing letter in 1st group
0  AA1 1A    Missing letter in 2nd group
0  AA1 1     Missing letter in 2nd group
;
run;

邮政编码可能会发生变化，验证邮政编码的唯一真正方法是拥有完整的邮政编码列表，并查看它是否存在。

但是正则表达式很有用，因为它们:

是否易于使用和实现 是短暂的 都跑得很快 相当容易维护(与完整的邮政编码列表相比) 仍然捕获大多数输入错误

但是正则表达式往往很难维护，特别是对于那些一开始就没有想到它的人来说。所以它一定是:

尽量简单易懂 相对未来的证明

这意味着这个答案中的大多数正则表达式都不够好。例如，我可以看到[a - pr - uwyz][a - hk - y][0-9][ABEHMNPRV-Y]将匹配形式为AA1A的邮政编码区域-但如果添加了新的邮政编码区域，这将是一个令人头疼的问题，因为很难理解它匹配哪些邮政编码区域。

我还想让我的正则表达式匹配邮政编码的前半部分和后半部分。

所以我想到了这个:

(GIR(?=\s*0AA)|(?:[BEGLMNSW]|[A-Z]{2})[0-9](?:[0-9]|(?<=N1|E1|SE1|SW1|W1|NW1|EC[0-9]|WC[0-9])[A-HJ-NP-Z])?)\s*([0-9][ABD-HJLNP-UW-Z]{2})

在PCRE格式中，可以这样写:

/^
  ( GIR(?=\s*0AA) # Match the special postcode "GIR 0AA"
    |
    (?:
      [BEGLMNSW] | # There are 8 single-letter postcode areas
      [A-Z]{2}     # All other postcode areas have two letters
      )
    [0-9] # There is always at least one number after the postcode area
    (?:
      [0-9] # And an optional extra number
      |
      # Only certain postcode areas can have an extra letter after the number
      (?<=N1|E1|SE1|SW1|W1|NW1|EC[0-9]|WC[0-9])
      [A-HJ-NP-Z] # Possible letters here may change, but [IO] will never be used
      )?
    )
  \s*
  ([0-9][ABD-HJLNP-UW-Z]{2}) # The last two letters cannot be [CIKMOV]
$/x

对我来说，这是尽可能多地验证之间的正确平衡，与此同时，未来的验证和易于维护。

虽然这里有很多答案，但我对其中任何一个都不满意。他们中的大多数只是简单地坏了，太复杂或只是坏了。

我看了@ctwheels的答案，我发现它非常具有解释性和正确性;我们必须为此感谢他。然而，对我来说，如此简单的事情又有太多的“数据”了。

幸运的是，我设法获得了一个数据库，其中仅包含英国的100多万个活动邮政编码，并编写了一个小型PowerShell脚本来测试和基准测试结果。

英国邮政编码规格:有效的邮政编码格式。

这是“我的”正则表达式:

^([a-zA-Z]{1,2}[a-zA-Z\d]{1,2})\s(\d[a-zA-Z]{2})$

简短，简单，甜蜜。即使是最没有经验的人也能明白发生了什么。

解释:

^ asserts position at start of a line
    1st Capturing Group ([a-zA-Z]{1,2}[a-zA-Z\d]{1,2})
        Match a single character present in the list below [a-zA-Z]
        {1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
        Match a single character present in the list below [a-zA-Z\d]
        {1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
        \d matches a digit (equivalent to [0-9])
        \s matches any whitespace character (equivalent to [\r\n\t\f\v ])
    2nd Capturing Group (\d[a-zA-Z]{2})
        \d matches a digit (equivalent to [0-9])
        Match a single character present in the list below [a-zA-Z]
        {2} matches the previous token exactly 2 times
        a-z matches a single character in the range between a (index 97) and z (index 122) (case sensitive)
        A-Z matches a single character in the range between A (index 65) and Z (index 90) (case sensitive)
$ asserts position at the end of a line

结果(已核对邮编):

TOTAL OK: 1469193
TOTAL FAILED: 0
-------------------------------------------------------------------------
Days              : 0
Hours             : 0
Minutes           : 5
Seconds           : 22
Milliseconds      : 718
Ticks             : 3227185939
TotalDays         : 0.00373516891087963
TotalHours        : 0.0896440538611111
TotalMinutes      : 5.37864323166667
TotalSeconds      : 322.7185939
TotalMilliseconds : 322718.5939

这个允许两边有空格和制表符，以防你不想验证失败，然后在另一边修剪它。

^\s*(([Gg][Ii][Rr] 0[Aa]{2})|((([A-Za-z][0-9]{1,2})|(([A-Za-z][A-Ha-hJ-Yj-y][0-9]{1,2})|(([A-Za-z][0-9][A-Za-z])|([A-Za-z][A-Ha-hJ-Yj-y][0-9]?[A-Za-z])))) {0,1}[0-9][A-Za-z]{2})\s*$)