正则表达式缺失模式

Question

I try to create a regex (PHP) that allow all digits,and allow only closed brackets with [digit-digit] format for exp.

0[1-3]xxx xx //valid
[1-3]xxx xx //valid
05[1-3]xxx xx //valid
0[1-3]555 6789 //valid
0332 555 6789 //valid

0[1-11]xxx xx //not valid
[1-3]xxxa xx //not valid

My regex pattern, [0-9]?\\[[0-9]-[0-9]\\][0-9 x]+ , validates the following:

[0-5]212xxx xx xx
[0-5]212xx xx xx
[0-5]212xx xx xx

...but it does not validate this string:

1231232131 

Change regex completely or edit the regex already but it seems getting complicated. How can I achieve my goal with most efficient way?

Answer 1

This pattern tests that string contains digit, construction [digit-digit] , space and character x

 ^(\d|\[\d-\d\]|x| )+$

or you can write it so:

^([\dx ]|\[\d-\d\])+$

demo and explanation