What are the different types of keywords in C language?

Keywords are generally called as pre-defined or reserved words in a programming language. Every keyword in C language performs a specific function in a program.

• Keywords cannot be used as variable names.

• Keywords have fixed meanings, and that meaning cannot be changed.

• They are the building block of a 'C' program.

• C supports 32 keywords.

• All the keywords are written in lowercase letters.

The different types of keywords are as follows −

Example

Given below is the C program for the Simple Calculator by using the Switch Case −

#include <stdio.h>
int main(){
   char Operator;
   float num1, num2, result = 0;
   printf("\n Try to Enter an Operator (+, -, *, /) : ");
   scanf("%c", &Operator);
   printf("\n Enter the Values for two Operands: ");
   scanf("%f%f", &num1, &num2);
   switch(Operator){
      case '+': result = num1 + num2;
      break;
      case '-': result = num1 - num2;
      break;
      case '*': result = num1 * num2;
      break;
      case '/': result = num1 / num2;
      break;
      default: printf("\n entered operator is invalid ");
   }
   printf("\n The result of %.2f %c %.2f = %.2f", num1, Operator, num2, result);
   return 0;
}

Output

When the above program is executed, it produces the following result −

Enter an Operator (+, -, *, /) : *
Enter the Values for two Operands: 34 12
The result of 34.00 * 12.00 = 408.00

In the above example, the keywords that are used to perform a simple calculator program are as follows −

Int, char, switch, case, break, float, default, return

These words cannot be used as variables while writing the program.