PHP Regular Expression not matching

Question

I have a really simple PHP regular expression that isn't returning as a match, as seen below.

if(preg_match('[0-9]{3}','123')){
    echo "match";
}
else{
    echo "nope";
}

This should check if the string '123' matches the pattern '[0-9]{3}', which of course it does - however it's not completing the true condition and is instead echoing "nope".

I've also tried:

if(preg_match('[0-9]{3}' '123') == '1'){
    echo "match";
}
else{
    echo "nope";
}

Any ideas? Do I need to configure my server or enable a regex property / library or something?

Answer 1

您忘记添加php分隔符 。

if(preg_match('~[0-9]{3}~','123')){