正则表达式检查字符串是否包含

Question

I need a regular expression. In order to check if a given string contains only [az][AZ][0-9] and a set of this char: .,|$_ .

In addition I need also a regex to check if the string contains at least one char for each of these 4 groups.

I'm working on PHP but I think regex are generic.

Answer 1

Look at the code. and try this.

$var = "stackoverflow";

if(preg_match('/[A-Z]|[a-z]|[0-9]|[.,$_]/', $var)) {
    echo "Matched";
}
else {
    echo "do not match";
}

That's it.

Thanks.

Answer 2

$var = "stackoverflow";

if( (preg_match('/[A-Z]{1}/', $var) &&
     preg_match('/[a-z]{1}/', $var) &&
     preg_match('/[0-9]{1}/', $var) &&
     preg_match('/[.,$_]{1}/', $var)) ) {
    echo "String matches and contains at least one character from each group.";
}
elseif(preg_match('/[A-Z]|[a-z]|[0-9]|[.,$_]/', $var)) {
    echo "String matches, but doesn't contain characters from all four groups.";
}
else {
    echo "String does not match.";
}