Output:
Red, Blue, Green
Red, Blue
Red.
Seope f Variables :

(i) Access control is a security technique that regulates who or what can view or use resources in a computing environment.
(ii) It is a fundamental concept in security that minimizes risk to the object.
(iii) In other words access control is a selective restriction of access to data.
(iv) In object oriented programming languages is implemented through access modifiers.

(i) All programming languages permit functions to be nested. A function (method) within another function is called nested function.
(ii) A variable which is declared, inside a function which contains another function definition with in it, the inner function can also access the variable of the outer function. This scope is called enclosed scope.
(iii) When a compiler or interpreter search for a variable in a program, it first searches Local, and then searches Enclosing scopes. Consider the following example

1. Disp(); 2. a:=10 3. Disp1(): 4. print a 5. Disp1() 6. print a 7. Disp()

Entire program

Output of the program 10 10

(i) A variable which is declared outside of all the functions in a program is known as Global variable.
(ii) This means, global variable can be accessed inside or outside of all the functions in a program. Consider the following example
1. a:=10
2. Disp():
3. a:=7
4. print a
5. Disp()
6. print a
Entire program

Output of the program
7 10 (iii) On execution of the above code the variable a which is defined inside the function displays the value 7 for the function call Disp() and then it displays 10, because a is defined in global scope.

(i) Local scope refers to variables defined in current function. Always, a function will first look up for a variable name in its local scope.
(ii) Only if it does not find it there, the outer scopes are checked.
(iii) Look at this example:

1. Disp(): 2. a:=7 3. print a 4. Disp()

Entire program

Output of the Program 7

(iv) On execution of the above code the variable a displays the value 7, because it is defined and available in the local scope.