public class JavaString { public static void main(String[] args) { String message = "Hello World"; String alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; System.out.println(alphabet.length()); // output 26 // check the length from a string varibale int messageLength = message.length(); // output: 11 System.out.println(messageLength); // make uppercase String lowerCaseToUpper = "md. sabbir hossain shuvo"; // alternative System.out.println(lowerCaseToUpper.toUpperCase()); System.out.println(lowerCaseToUpper.toUpperCase()); String findAge = "My age is 20"; // Output: 10 System.out.println(findAge.indexOf("20"));// it is start counting from 0 since 20 belong into the 10 number // index then output is 10 } }