Mega Code Archive
Scope class demonstrates field and local variable scopes
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public class MainClass
{
public static void main( String args[] )
{
Scope testScope = new Scope();
testScope.begin();
}
}
class Scope
{
private int x = 1;
public void begin()
{
int x = 5; // method's local variable x shadows field x
System.out.printf( "local x in method begin is %d\n", x );
useLocalVariable();
useField();
useLocalVariable();
useField();
System.out.printf( "\nlocal x in method begin is %d\n", x );
}
public void useLocalVariable()
{
int x = 25; // initialized each time useLocalVariable is called
System.out.printf("\nlocal x on entering method useLocalVariable is %d\n", x );
++x; // modifies this method's local variable x
System.out.printf(
"local x before exiting method useLocalVariable is %d\n", x );
}
// modify class Scope's field x during each call
public void useField()
{
System.out.printf("\nfield x on entering method useField is %d\n", x );
x *= 10; // modifies class Scope's field x
System.out.printf("field x before exiting method useField is %d\n", x );
}
}
local x in method begin is 5
local x on entering method useLocalVariable is 25
local x before exiting method useLocalVariable is 26
field x on entering method useField is 1
field x before exiting method useField is 10
local x on entering method useLocalVariable is 25
local x before exiting method useLocalVariable is 26
field x on entering method useField is 10
field x before exiting method useField is 100
local x in method begin is 5
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