non static method cannot be referenced from a static context [duplicate]

Question

First some code:

import java.util.*;
//...

class TicTacToe 
{
//...

public static void main (String[]arg) 
{ 

    Random Random = new Random() ; 
    toerunner () ; // this leads to a path of 
                   // methods that eventualy gets us to the rest of the code 
} 
//... 

public void CompTurn (int type, boolean debug) 
{ 
//...

        boolean done = true ; 
        int a = 0 ; 
        while (!done) 
        { 
            a = Random.nextInt(10) ;
            if (debug) { int i = 0 ; while (i<20) { System.out.print (a+", ") ; i++; }} 
            if (possibles[a]==1) done = true ; 
        } 
        this.board[a] = 2 ; 


}
//...

} //to close the class 

Here is the error message:

TicTacToe.java:85: non-static method nextInt(int) cannot be referenced from a static context
            a = Random.nextInt(10) ;
                      ^

What exactly went wrong? What does that error message "non static method cannot be referenced from a static context" mean?

Answer 1

You are calling nextInt statically by using Random.nextInt.

Instead, create a variable, Random r = new Random(); and then call r.nextInt(10).

It would be definitely worth while to check out:

• What is the reason behind "non staticmethod cannot be referenced from a static context"?

Update:

You really should replace this line,

Random Random = new Random(); 

with something like this,

Random r = new Random();

If you use variable names as class names you'll run into a boat load of problems. Also as a Java convention, use lowercase names for variables. That might help avoid some confusion.

Answer 2

You're trying to invoke an instance method on the class it self.

You should do:

    Random rand = new Random();
    int a = 0 ; 
    while (!done) { 
        int a = rand.nextInt(10) ; 
    ....

Instead

As I told you here stackoverflow.com/questions/2694470/whats-wrong...