LOCAL VARIABLES AND GLOBAL VARIABLES.pptx
- 1. LOCAL VARIABLES & GLOBAL VARIABLES Presented by:- Atul Sahu
- 2. What is a Variable ? A variable is a data name that may be used to store a data value. A variable may take different values at different times of execution and may be chosen by the user. it may consist of letters, digits and underscore character. •Importance in programming Variables are essential for managing data in a program. they enables developers to store values of various data types, such as strings, integers and floats, which can be used to perform calculations manipulate text, or control program flow.
- 3. Scope of Variable Each variable is defined and can be used within its scope and determines that wherein the program this variable is available to use. The scope means the lifetime of that variable. It means the variable can only be accessed or visible within its scope. The scope of variables can be defined with their declaration, and variables are declared mainly in two ways.
- 4. Local Variable Local variables are variables that are declared within a specific scope, such as inside a function or a block of code. Example- #include<stdio.h> Void main() { Int X=24, Y=4; Printf(“X=%d and Y=%d”,X,Y); }
- 5. Global Variable Global variables are variables that are declared outside of any function or block of code. Example- #include<conio.h> Int A=10, B; Void main() { Printf(‘A=%d and B=%d”,A,B); }
- 7. It is declared inside a function. It is declared outside the function. If it is not initialized, a garbage value is stored. If it is not initialized zero is stored as default. It is created when the function starts execution and lost when the functions terminate. It is created before the programs global execution starts and lost when the program terminate. Data sharing is not possible as data of the local variable can be accessed by only one function. Data sharing is possible as multiple functions can access the same global variable. When the value of the local variable is modified in one function, the changes are not visible in another fuction. When the value of the global variable is modified in one function, the changes are visible in rest of the program. Local variables can be accessed inside a function in which they are declared. you can access global variables be any statement in the program.
- 8. WHEN TO USE LOCAL OR GLOBAL VARIABLE - If you feel that a certain variable will take multiple values by passing through various functions then use local variables . If you feel that a certain variable you need to use will have constant value, then declare it as a global variable.
- 9. Advantages Of Local Variable:- The same name of a local variable can be used in different functions as it is only recognized by the function in which it is declared. Local variables use memory only for the limited time when the function is executed, after that same memory location can be reused Disadvantages Of Local Variable:- The scope of the local variable is limited to its function only and cannot be used by other functions. Data sharing by the local variable is not allowed.
- 10. Advantages Of Global Variable:- Global variables can be accessed by all the functions present in the program. Only a single declaration is required. Very useful if all the functions are accessing the same data. Disadvantages Of Global Variable:- The value of a global variable can be changed accidently as it can be used by any function in the program. If we use a large number of global variables, then there is a high chance of error generation in the program.
- 11. Example Of Local & Global Variable In Python:
- 12. Thank you