Overloading doubt

[Jacob Sonia]

    import java.util.*;
public class NewVarArgs{
	static void printArray(Object... args){
		System.out.println("Object");
		for(Object obj: args){
			System.out.println(obj);
		}
	}
	
	static void printArray(Integer... args){
		System.out.println("Integer");
		for(Integer s: args){
			System.out.println(s);
		}
	}
	public static void main(String[] args){
		printArray(new Integer[]{1,2,3,4,5,});
		printArray();
	}
}

I am in doubt that if i write the above program, i don't get any ambiguity error but when i add this method into it i get one. Please explain.

  import java.util.*;

	static void printArray(String... args){
		System.out.println("String");
		for(String i: args){
			System.out.println(i);
		}
	}
	  

[Ankit Garg]

Take a look at the following code

class MyClass {
	public static void main(String[] args) {
		ambiguity(null);
	}
	static void ambiguity(Object o) {}
	static void ambiguity(Integer i) {}
	//static void ambiguity(String s) {}
}

If you uncomment the third ambiguity method, then there will be an ambiguity error. As the code stands, you won't get any error because null can be passed to Object and Integer but since Integer is more specific (as its a sub-class of Object), thus the method which takes Integer is chosen. If you uncomment the third ambiguity method, then compiler is not able to choose which method should be called. Integer and String are both in different hierarchies. The same thing happens in your code too. When you don't pass any parameters, if there are 2 methods which take Object... and Integer..., then the one with Integer... is chosen. But if you introduce the third method, then the compiler is not able to choose between String... and Integer...