Operators in C

Arithmetic Operators

• Addition: +
• Subtraction: -
• Multiplication: *
• Division (both integer and real): /
  • integer/integer yields an integer (7/4 is 1)
  • float/integer yields a float (7.0/4 is 1.75)
  • integer/float yields a float
  • float/float yields a float
• Modulus (remainder after integer division): %
  • integer%integer yields an integer (7%4 is 3)

Assignment Operators

• Simple assignment: =
  • number = 27
• Increment by 1: ++ (equivalent to number = number + 1)
  • number++ (number is now 28)
  • ++number (number is now 29)
• Decrement by 1: -- (equivalent to number = number - 1)
  • number-- (number is now 28)
  • --number (number is now 27)
• Compound Assignment : operator= (+=, -=, *=, /=, etc.)
  • number += 20 (number is now 47) (equivalent to number = number + 20)

Relational Operators

• Less than: <
• Greater than >
• Less than or equal: <=
• Greater than or equal: >=
• Equal: ==
• Not equal: !=

Logical Operators

• And: &&
• Or: ||
• Not: !

Do NOT use the bitwise operators as logical operators. They are not the same things.
• Bitwise and: &
• Bitwise or: |

• (a > b) && (c++ < 12)
  If a is not greater than b then the second relationship is not evaluated since both must be true for the whole thing to be true.
• (a > b) || (c++ < 12)
  If a is greater than b then the second relationship is not evaluated since if either of the parts is true, the whole thing is true.

Pointer Operators

• Declaration specifier: *
• Address of: &
• Dereference: *

  int number = 12;
  int *ptr_to_int;

  ptr_to_int = &number;
  printf("\nValue = %d", *ptr_to_int);