help please...what is wrong in this code?

public class Friend { String name; int age; char sex; public void initialize(String name){ this.name = name; } public void initialize(String name , int age){ this.name = name; this.age = age; } public void initialize(String name , int age, char sex){ this.name = name; this.age = age; this.sex = sex; } public static void main(String[] args) { Friend obj1 = new Friend(); System.out.println(obj1.initialize("a")); Friend obj2 = new Friend(); System.out.println(obj2.initialize("a",18)); Friend obj3 = new Friend(); System.out.println(obj3.initialize("a",19,'M')); } }