Operators

Operators are used to perform operations on variables and values. They are symbols that tell the compiler to perform specific mathematical or logical functions. The C language provides the following types of operators:

  • Arithmetic Operators
  • Relational Operators
  • Logical Operators
  • Bitwise Operators
  • Assignment Operators
  • Misc Operators

Arithmetic Operators

C has the following basic arithmetic operators to perform common mathematical operations:

Operator Name Description
+ Addition x + y returns the sum of x and y
- Subtraction x - y returns the difference of x and y
* Multiplication x * y returns the product of x and y
/ Division x / y returns the quotient of x and y
% Modulo x % y returns the integer remainder of x divided by y
++ Increment x++ returns x + 1
-- Decrement x-- returns x - 1
int x = 0;
x = x + 4; // x is now 4
x = x - 1; // x is now 3
x = x * 8; // x is now 24
x = x / 4; // x is now 6
x = x % 4; // x is now 2
x++; // x is now 3
x--; // x is now 2

Relational Operators

Relational operators compare two values and return true or false.

Operator Name Description
== Equal x == y is true if x and y are equal.
!= Not Equal x != y is true if x and y are not equal.
< Less Than x < y is true if x is less than y.
> Greater Than x > y is true if x is greater than y.
<= Less Than or Equal to x <= y is true if x is less than or equal to y.
>= Greater Than or Equal to x >= y is true if x is greater than or equal to y.
int x = 7;
int y = 5;
if (x > y) {
// This code will run.
}
if (x == y) {
// This code won't run.
}

Logical Operators

Logical operators operate on boolean values and return boolean values.

Operator Name Description
! Not !x is true when x is false and false when x is true.
&& And x && y is true only if x and y are both true.
|| Or x || y is true if either x or y is true.
int x = 7;
int y = 5;
if (x > y \|\| x == y) {
// This code will run.
}
if (x == y && x < 0) {
// This code won't run.
}

Bitwise Operators

Bitwise operators manipulate individual bits in an integer.

Operator Name Description
& And Result has bit set only where both operands have that bit set.
| Or Result has bit set if either operand has that bit set.
^ Xor Result has bit set only if only one operand has that bit set.
~ Not Takes a single operand and inverts each bit in it.
<< Left shift a << b means a‘s bits are shifted to the left b spaces.
>> Right shift a >> b means a‘s bits are shifted to the right b spaces.
int x;
x = 19 & 7;
// x is 3 : 10011 & 00111 = 00011
x = 19 | 7;
// x is 23 : 10011 | 00111 = 10111
x = 19 ^ 7;
x is 20 : 10011 ^ 00111 = 10100
x = 7 << 2;
// x is 28 : 00111 << 2 = 11100
x = 19 >> 2;
// x is 4 : 10011 >> 2 = 00100

Assignment Operators

Assignment operators assign the value on the right to the variable on the left.

Operator Name Description
= Assignment a = 3 assigns value 3 to variable a.
+= Addition Assignment a += 3 is short for a = a + 3.
-= Subtraction Assignment a -= 3 is short for a = a - 3.
*= Multiplication Assignment a *= 3 is short for a = a * 3.
/= Division Assignment a /= 3 is short for a = a / 3.
%= Modulo Assignment a %= 3 is short for a = a % 3.
&= And Assignment a &= 3 is short for a = a & 3.
|= Or Assignment a |= 3 is short for a = a | 3.
^= Xor Assignment a ^= 3 is short for a = a ^ 3.
<<= Left Shift Assignment a <<= 3 is short for a = a << 3.
>>= Right Shift Assignment a >>= 3 is short for a = a >> 3.

Misc Operators

Misc operators don’t fit into a particular category.

Operator Name Description
sizeof() Addition Assignment sizeof(x) returns the size of variable x.
& Address &x returns the address of variable x.
* Pointer *x returns a pointer to variable x. Not to be confused with multiplication.
?: Conditional Operator expression?x:y returns x when expression is true, y otherwise.
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