I need an explanation as to why this is the output. Thanks in advance

public class Launcher public static void main(String args) Yy=new Y("SMU"); y.2) system.out.println(y)i )/end Launcher public class Y private String a; public Y(String s) System.out.println("ABC" public void z) System.out.println( "XYZ") public String tostring) return a; /lend Y OUTPUT: ABC XYZ SMU