CODEWITHSUNDEEP
java
shippingyard
shippingyard

Reputation: 13

Unable to call function in java

When I try to call the lyrics function in this code, "invalid method declaration; return type required" occurs. I'm learning java and very very new to it. I'm confused how to define the function and call the function so that code may run.

public class Main {
    public static void main(String[] args) {
    }
    public void lyrics() {
        System.out.println("some lyrics here");
    }
    lyrics();
}

Upvotes: 1

Views: 456

Answers (5)

PaulProgrammer
PaulProgrammer

Reputation: 17630

You need to move the call to lyrics() into the main method where code is actually executed. Where you have it now, the compiler is expecting a new method defination.

public class Main {
    public static void main(String[] args) {
        // execution begins here.
        new Main().lyrics();
    }
    public void lyrics() {
        System.out.println("some lyrics here");
    }
}

EDIT: created new class Main class to avoid errors.

Upvotes: -1

Piyush Patel
Piyush Patel

Reputation: 1751

Your code is nearly correct. Your lyrics() method must be static if you want to call it inside main method because main method is static. Non static members cannot be accessed from static method (without creating an instance to invoke it).

public class Main {
    public static void main(String[] args) {
        lyrics();
    }
    public static void lyrics() {
        System.out.println("some lyrics here");
    }

}

You can invoke non-static methods from static method by creating an instance of the class containing non-static method inside your main method as mentioned in comments by Elliott Frisch.

new Main().lyrics();

Upvotes: 1

coderfromhell
coderfromhell

Reputation: 455

Since you're learning Java, you must remember that the only way to call a non-static method from a static method is to have an instance of the class containing the non-static method.

Or you can simply make your function static. Also, you need to call the function inside the main block. 

public class Main {
    public static void main(String[] args) 
    {
        lyrics();
    }
    public static void lyrics() 
    {
        System.out.println("some lyrics here");
    }
}

Happy coding!

Upvotes: 0

Elliott Frisch
Elliott Frisch

Reputation: 201439

Normally, one can't just invoke a method randomly in the body of the code. However, there is something called an initialization block (this gets run in the body of the constructors of the object). I think an example might clarify. Like,

public class Main {
    public static void main(String[] args) {
        new Main(); // <-- instantiate an instance of Main
    }
    public void lyrics() {
        System.out.println("some lyrics here");
    }
    { // <-- this is an initialization block
        lyrics();
    }
}

The above uses the default constructor, we can add an explicit one. Like,

public Main() {
    super();
    System.out.println("In Main constructor");
}

Note how the output changes.

They can also be static (and run when the class is first referenced). Like,

public class Main {
    public static void main(String[] args) {
    }
    public static void lyrics() {
        System.out.println("some lyrics here");
    }
    static {
        lyrics();
    }
}

Upvotes: 1

Subham Banerjee
Subham Banerjee

Reputation: 63

The method should be declared as static and function call should be within main method. The correct code should look like as follows:

public class Main {
    public static void main(String[] args) 
    {
        lyrics();
    }
    public static void lyrics() 
    {
        System.out.println("some lyrics here");
    }

}

Upvotes: 0

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