Regex doesn't work in String.matches()

Question

I have this small piece of code

String[] words = {\"{apf\",\"hum_\",\"dkoe\",\"12f\"};
for(String s:words)
{
    if(s.matches(\"[a-z]\"))
    {
        Syste         


        

Answer 1

[a-z] matches a single char between a and z. So, if your string was just "d", for example, then it would have matched and been printed out.

You need to change your regex to [a-z]+ to match one or more chars.

Answer 2

Used

String[] words = {"{apf","hum_","dkoe","12f"};
    for(String s:words)
    {
        if(s.matches("[a-z]+"))
        {
            System.out.println(s);
        }
    }

Answer 3

you must put at least a capture () in the pattern to match, and correct pattern like this:

String[] words = {"{apf","hum_","dkoe","12f"};
for(String s:words)
{
    if(s.matches("(^[a-z]+$)"))
    {
        System.out.println(s);
    }
}