How can I check if an input is a integer or String, etc.. in JAVA?

Question

I am wondering how I can check if a user\'s input is a certain primitive type (I mean integer, String, etc... I think it\'s called primitive type?). I want a user to input s

Answer 1

You may try this with Regex:

String input = "34";
if(input.matches("^\\d+(\\.\\d+)?")) {
  //okay
} else {
  // not okay !
}

Here,

^\\d+ says that input starts with a digit 0-9,

()? may/or may not occur

\\. allows one period in input