Calling a local variable from a static function

Thu Dec 10, 2009 6:17 pm

Calling local variable from inside a static method:

Following code has this problem :

Code:: class Boat { int calcDir() { int direction = 2; return direction; } } public class Control { public static void main(String args[]){ Boat boat = new Boat(); boat.calcDir(); System.out.println(direction); } }

I always get the same error:
cannot find symbol
Symbol : variable direction
Location : class Control

In this case you are calling local variable of a method calcDir() inside another class from a static method. The scope the of int direction , is the function calcDir() only.

Code:: class Boat { int direction; int calcDir() { return direction + 1; } } public class Control { public static void main(String args[]){ int direction = 2; Boat boat = new Boat(); System.out.println(boat.calcDir()); } }

Sat Dec 12, 2009 11:56 pm

the int direction inside the calcDir() method , has a value of 0 . ( which is the default value of int ) . so the 0 + 1 = 0 ;

the int direction inside the main method , it's scope is bounded to the main method only . Not seen inside the class Boat .

Sun Dec 13, 2009 8:13 pm

So how do I store the calculated value in calcDir() to be able to use it in class Control?

Sun Dec 27, 2009 1:53 am

Since you working with 2 classes here you need to set a variables value with the calcDir() method

The first way...

Code:: class Boat { int calcDir() { int direction = 2; return direction; } } public class Control { public static void main(String args[]){ //Declare a variable to hold the return value of calcDir() int tempDir = 0; Boat boat = new Boat(); //Use the calcDir() method to fill the value of tempDir tempDir = boat.calcDir(); //Print the value System.out.println(tempDir); } }

The second way is to pass in a variable amount as a parameter to the calcDir() method...

Code:: class Boat { int calcDir(int tVal) { //Pass in a value as a parameter to the calcDir() method //This Value will get incremented by 1 return tVal + 1; } } public class Control { public static void main(String args[]){ int direction = 2; Boat boat = new Boat(); System.out.println(boat.calcDir(direction)); } }

Calling a local variable from a static function

Calling a local variable from a static function

Re: What's wrong?

Re: What's wrong?

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