PHP正则表达式数字加一个字母

Question

I'm trying to achieve validation for numeric input plus letter X or x. So far I have:

if(preg_match('/[^0-9xX]+$/', $data)) return 'error';

It correctly returns error for all cases EXCEPT a123. Have anyone idea why?

Answer 1

Use ^ at the start of regex to check if the complete string instead of sub-string.

if(preg_match('/^[0-9xX]+$/', $data))
    return 'error';

Answer 2

Try this:

if(preg_match('/^[0-9x]+$/i', $data)){
 echo 'match';
}else{
 echo 'no match';
}

Its like yours, only the other way round. ^ is for the begin of the string. $ For the end of the string. So the whole string must match the pattern.

Answer 3

if(!preg_match('/^([0-9]+|[xX])$/', $data)) return 'error';

Maybe this would be better, it match the right case,and add ! before match result.

Answer 4

I don't got it.

if(preg_match('/^[0-9xX]+$/', $data)) return 'error';

still doesn't return error when we enter 123.

I'm sorry if i make misunderstanding.

if(preg_match('/[0-9]xX$/', $data)) return 'error';

All number will be followed by xX. CMIIW.