String Function in JAVA

  say hy 

package com.company;
import java.util.Scanner;

public class say_hy {
    public static void main (String[] arg)
    {
        Scanner s=new Scanner(System.in);
        System.out.println("enter your name");
        String a= s.nextLine();
        System.out.print(" hello, ");
        System.out.println(a);

    }
}

string (length , LowerCase,  UpperCase)

package com.company;

import java.util.Locale;

public class strings {
    public static void main(String[] args) {
        String name = ( "vishal rana" );
        System.out.println(name);

            int len = name.length();
            System.out.printf("the number of letters in string are %d",len);
            String l= name.toLowerCase();
        System.out.println(l);
        String u= name.toUpperCase();
        System.out.println(u.substring(3));
    }

}

string (replace function)

package com.company;
import java.util.Scanner;
public class to_ {
    public static void main(String[] args) {
        Scanner s = new Scanner(System.in);
        System.out.println("Enter a string");
        String s1 = s.nextLine();
        String s2 = s1.replace( " ", "_") ;
        System.out.println(s2);

    }
}