Arithmetic Instruction

Arithmetic instruction is used to manipulate data using operators
To understand operators in a better way we put them in 7 groups.

  • Unary Operators
  • Arithmetic Operators
  • Bitwise Operators
  • Relational Operators
  • Logical Operators
  • Conditional Operators
  • Assignment Operators

      • Unary Operators
      Operator require operands to perform its operation. Unary operators are those, which takes one operand to perform its task.

      Unary + and –
      These operators should not be misinterpreted as addition and subtraction operators. These are unary + and –, used to make sign positive or negative. For example -3, +4, -345 etc

      Increment Operator

      • It increments the value of the operand by 1 (one).
      • Operand must be a variable.

      Example

      int main()
      {
      int x=5;
      x++;
      printf("%d ",x);
      ++x;
      printf("%d ",x);
      return(0);
      }
      Output
      6 7

      • The value of variable x is initialized to 5.
      • In x++, x is an operand and ++ is an operator. Operator is better known as post-increment.
      • x++ increases value of variable x by 1, that is value becomes 6
      • printf(“%d “,x); prints 6
      • In ++x, operator is better known as pre-increment operator
      • ++x again increases the value by 1, that is it becomes 7
      • printf(“%d “,x); prints 7

      Job of pre-increment and post-increment operators are same but there is a difference in priority. Pre-increment has higher priority than post-increment. In fact, post-increment has the least priority among all the operators.
      Example

      int main()
      {
      int x=5,y;
      y=x++;
      printf("%d %d",x,y);
      return(0);
      }

      Output
      6 5

      There are two operators in expression y=x++. Assignment operator (=) has higher priority than post increment operator, therefore, value of x is copied to variable y. The value of y becomes 5. Now post-increment operator increases the value of variable x by 1. The variable x becomes 6.

      sizeof operator
      sizeof() operator is used to evaluate the size of data type, variable or constant.
      Example :
      int main()
      {
      int x,y;
      float k;
      char ch;
      double d;
      x=sizeof(float); // sizeof returns 4 and assigned to x
      x=sizeof(char); // sizeof returns 1 and assigned to x
      x=sizeof(int); // sizeof returns 4 and assigned to x
      x=sizeof(double); // sizeof returns 8 and assigned to x
      x=sizeof(d); // sizeof returns 8 and assigned to x
      x=sizeof(k); // sizeof returns 4 and assigned to x
      x=sizeof(ch); // sizeof returns 1 and assigned to x
      x=sizeof(y); // sizeof returns 4 and assigned to x
      x=sizeof(45); // sizeof returns 4 and assigned to x

      x=sizeof(23.67); // sizeof returns 8 and assigned to x
      x=sizeof(‘a’); // sizeof returns 4 and assigned to x
      return(0);
      }

      Unary Operators