regex for zip-code

Question

Possible Duplicate:
What is the ultimate postal code and zip regex?

I need Regex which can satisfy all my thr

Answer 1

For the listed three conditions only, these expressions might work also:

^\d{5}[-\s]?(?:\d{4})?$
^\[0-9]{5}[-\s]?(?:[0-9]{4})?$
^\[0-9]{5}[-\s]?(?:\d{4})?$
^\d{5}[-\s]?(?:[0-9]{4})?$

Please see this demo for additional explanation.

If we would have had unexpected additional spaces in between 5 and 4 digits or a continuous 9 digits zip code, such as:

123451234
12345 1234
12345  1234

this expression for instance would be a secondary option with less constraints:

^\d{5}([-]|\s*)?(\d{4})?$

Please see this demo for additional explanation.

RegEx Circuit

jex.im visualizes regular expressions:

Test

const regex = /^\d{5}[-\s]?(?:\d{4})?$/gm;
const str = `12345
12345-6789
12345 1234
123451234
12345 1234
12345  1234
1234512341
123451`;
let m;

while ((m = regex.exec(str)) !== null) {
    // This is necessary to avoid infinite loops with zero-width matches
    if (m.index === regex.lastIndex) {
        regex.lastIndex++;
    }
    
    // The result can be accessed through the `m`-variable.
    m.forEach((match, groupIndex) => {
        console.log(`Found match, group ${groupIndex}: ${match}`);
    });
}