Local variables:
- A variable inside the function or block.
- Local variable cannot access outside of that block.
| int main() { int a ; -> local variable } |
Local variables automatically initialize with garbage values. We cannot guess garbage value.
| #include<stdio.h> int main() { int a; printf(“%d \n”, a); -> Prints unknown value. return 0; } |
Format specifiers:
- Formatting the result is very important before display to user.
- We use following format specifiers to read and print different types of data values.
| Data type | Format specifier |
| int | %d |
| char | %c |
| float | %f |
| string | %s |
Display information of different data types:
| #include<stdio.h> int main () { char* name = “Amar”; int age = 23; float salary = 35000; char gender = ‘M’; printf(“Name is : %s \n”, name); printf(“Age is : %d \n”, age); printf(“Salary is : %f \n”, salary); printf(“Gender is : %c \n”, gender); return 0; } |
We can access local variables only from the same function in which they have defined.
| #include<stdio.h> void test(); int main () { int a=10; printf(“a value in main : %d \n”, a); test(); return 0; } void test() { printf(“a value in test :%d \n”, a); // Error : } |
Global Variables:
- Defining a variable outside to all functions.
- Global variables can be accessed from all the functions.
| #include<stdio.h> void test(); int a=10; int main (){ printf(“a value in main : %d \n”, a); test(); return 0; } void test(){ printf(“a value in test :%d \n”, a); } |
Global variables automatically initialize with default values:
| Datatype | Default Value |
| int | 0 |
| float | 0.00000 |
| char | Blank |
| string | Null |
| #include<stdio.h> int a; float b; int main () { printf(“int : %d \n”, a); printf(“float : %f \n”, b); return 0; } |