Types of Variables in C Language
Categories: C language
There are many types of variables in c:
1. local variable
2. global variable
3. static variable
4. automatic variable
5. external variable
Local Variable
A variable that is declared inside the function or block is called a local variable.
It must be declared at the start of the block.
void function1(){
int x=10;//local variable
}
You must have to initialize the local variable before it is used.
Global Variable
A variable that is declared outside the function or block is called a global variable. Any function can change the value of the global variable. It is available to all the functions.
It must be declared at the start of the block.
int value=20;//global variable
void function1(){
int x=10;//local variable
}
Static Variable
A variable that is declared with the static keyword is called static variable.
It retains its value between multiple function calls.
void function1(){
int x=10;//local variable
static int y=10;//static variable
x=x+1;
y=y+1;
printf("%d,%d",x,y);
}
Automatic Variable
All variables in C that are declared inside the block, are automatic variables by default. We can explicitly declare an automatic variable using auto keyword.
void main(){
int x=10;//local variable (also automatic)
auto int y=20;//automatic variable
}
External Variable
We can share a variable in multiple C source files by using an external variable. To declare an external variable, you need to use extern keyword.