Constant

Constant is also a value or variable,but only difference is their values cannot be change by the program once they are defined.Constant are also referd a fixed values and constants may be belonging to any of the data type.

Type of Constant :-

There are two ways to define constant

• Const keyword
• #define Preprocessor

• Const keyword: In C const keyword are used to declare the constants with a specific typeconst type variable = value;
  For Example :-

  #include<stdio.h>
   void main()
   {
   const int height = 100;
   printf("The value of height is :%d", height);
  return 0;
   }

  Now the value of height cannot be changed.

  Output

  The value of height is : 100

  If you change the value of height, you will get an error at the compile time.

• #define Preprocessor: The #define Preprocessor directive is used to define constant substitution and #define preprocessor are use with specific type
  #define identifier value

  Let’s see the example of #define

  #include<stdio.h>
  #define height=100
  int main(){
  printf("%d",height);
  }

  Output

  100