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javascriptregexzipcode

Regular expression for Dutch zip / postal code

I'm trying to build a regular expression in javascript to validate a Dutch zipcode.

The zipcode should contain 4 numbers, then optionally a space and then 2 (case insensitive) letters

Valid values: 

1001aa  
1001Aa  
1001 AA

I now have this, but it does not work:

var rege = /^([0-9]{4}[ ]+[a-zA-Z]{2})$/;
Solution

  • Edited to handle no leading 0 requirement for Dutch postal codes, and to eliminate matches for SS, SA, and SD. This should do it all for you.

    Final regex:

    var rege = /^[1-9][0-9]{3} ?(?!sa|sd|ss)[a-z]{2}$/i;

    Fiddle unit test: http://jsfiddle.net/hgU3u/

    Here's a breakdown:

    1. ^ matches beginning of string
    2. [1-9][0-9]{3} matches a single non-zero digit, and three 0-9 digits
    3. ? matches 0 or 1 spaces (you could use * to match 0 or more spaces)
    4. (?!sa|sd|ss) is a lookahead test to check that the remainder is not "sa", "sd", or "ss".
    5. [a-z]{2} matches 2 a-z characters
    6. $ matches the end of the string
    7. i at the end is the case-insensitive modifier