Question

What is the best way to compare that given String start With another String

Example :

  if("ABCD1234".startsWith("ABCD")){
        System.out.println("This is true ");
    }

    if("ABCD1234".substring(0,4).equalsIgnoreCase("ABCD")){
        System.out.println("This also true ");
    }

Or are there any other solutions ?

Answer 1

I think startsWith() is the best option since it makes your intention clear to anyone reading your code. If you want it to be case-insensitive convert both values to the same case before calling the method.

String prefix = "ABCD";
prefix = prefix.toLowerCase();

if("ABCD1234".toLowerCase().startsWith(prefix)) {
    System.out.println("This is true ");
}

If you want to be extra careful you may want to pass a Locale to toLowerCase() or at least be sure to call it on both Strings to ensure your code passes the Turkey Test.