Java - how to load method inside class it is defined?

Question

For example I have this code:

public class A
{
    private void my_method(){
        //do something
    }
}

So how can I call that method for code below to use it? I saw in one example it was done like this:

public class A
{
    public A {
        my_method();
    }

    //some other code

    private void my_method(){
        //do something
    }
}

But trying this gives me this error:

"Syntax error on token "public", class expected after this token"

And of course using advise in error, gives this error:

"The nested type A cannot hide an enclosing type" So it seems that code I saw is bad or somehow I'm doing something wrong. Anyone could explain how to do it properly in Java?

forgot to add the braces it should be public A() { instead of public A { — Deepak Bhatia, Oct 10 '13 at 12:47
@dbw thanks. That worked. It seems it was mistake in a code I saw. You can post in as answer, so everyone would see if someone gets the same problem :) — Andrius, Oct 10 '13 at 12:50
@Andrius thanks for reply, we are here to solve your problems and my comment could solve your problem that's more then enough rather then posting an answer — Deepak Bhatia, Oct 10 '13 at 13:07

score 7 · Answer 1 · edited Oct 10 '13 at 12:59

7

Your constructor is wrong (you forgot the brackets).

It has to be

public A() {

}

edited Oct 10 '13 at 12:59

Maroun

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answered Oct 10 '13 at 12:46

Jeroen Vannevel

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3

parentheses, not brackets – Math Oct 10 '13 at 12:48
That wouldn't be confusing at all if all programmers started saying brackets to all the types of brackets. – spydon Oct 10 '13 at 12:54
1

`Brackets extends Parentheses`. – Maroun Oct 10 '13 at 12:58
I really didn't know this definition. It is correct, so. But I'd rather keep saying parentheses for a matter of clarification. – Math Oct 10 '13 at 12:59
@MarounMaroun actually, it is the oppose, parentheses extends brackets, right? – Math Oct 10 '13 at 12:59
@Math Actually I didn't consider the details, it was a joke (a bad one) :D – Maroun Oct 10 '13 at 13:02
Well.. Perhaps I have to stop correcting people, your joke is good, I liked :) – Math Oct 10 '13 at 13:03

score 0 · Answer 2 · answered Oct 10 '13 at 12:49

0

You are getting this error because you have not wrote the constructor correctly. It should be:

public A() {
    my_method();
}

answered Oct 10 '13 at 12:49

Scott Pearson

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4

score 0 · Accepted Answer · answered Oct 10 '13 at 12:49

0

constructor is missing (). use

public A() { }

answered Oct 10 '13 at 12:49

codingenious

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score 0 · Answer 4 · answered Oct 10 '13 at 12:57

Just to expand on Jeroen's answer as it seems you are quite new to Java:

Your private method can be called from inside another method in your class. E.g.

public class A
{
    public void anotherMethod() {
        my_method();
    }

    private void my_method(){
        //do something
    }
}

The code you provided was called within the constructor of the class. This is a special method which is called when an object of type A is constructed e.g. new A();. You can tell it's a constructor because it has no return type specified:

public A() {
}

rather than a normal method:

public void a() {
}

Something to note there is that in Java it is convention (but not strictly required) to name normal methods with a lowercase first letter and classes/objects/constructors with an upper case first letter.

So your mistake was that in your constructor you had not put () after the method name (A in this case).

Java - how to load method inside class it is defined?

4 Answers4