Two Main methods with different signatures

Question

I have following class.

public class Test {

    public static void main(Integer[] args) {
        System.out.println("This is not a main"); 
    }   

    public static void main(String[] args) {
        System.out.println("This is the main"); 
    }
}

In here there are two main method which are accept Integer[] and String [] as input argument. My question is how JVM always load second method as main method of this class. Why always consider input argument as array of String?

Answer 1

Because that's what Java always looks for. Java Language Specification, Section 12.1.4:

The method main must be declared public, static, and void. It must specify a formal parameter (§8.4.1) whose declared type is array of String

Answer 2

Because Strings are what you're passing into the command line.

the 45 from

myProgram.exe 45

is not an integer. it is a string containing the characters 4 and 5

It just so happens that you can use a string like "45" to represent an integer. It's a little more difficult to do it the other way around.(for the user at least)