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C Operators


Operators

Operators are used to perform operations on variables and values.

In the example below, we use the + operator to add together two values:

Example

int myNum = 100 + 50;
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Although the + operator is often used to add together two values, like in the example above, it can also be used to add together a variable and a value, or a variable and another variable:

Example

int sum1 = 100 + 50;        // 150 (100 + 50)
int sum2 = sum1 + 250;      // 400 (150 + 250)
int sum3 = sum2 + sum2;     // 800 (400 + 400)
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C divides the operators into the following groups:

  • Arithmetic operators
  • Assignment operators
  • Comparison operators
  • Logical operators
  • Bitwise operators

Arithmetic Operators

Arithmetic operators are used to perform common mathematical operations.

Operator Name Description Example Try it
+ Addition Adds together two values x + y Try it »
- Subtraction Subtracts one value from another x - y Try it »
* Multiplication Multiplies two values x * y Try it »
/ Division Divides one value by another x / y Try it »
% Modulus Returns the division remainder x % y Try it »
++ Increment Increases the value of a variable by 1 ++x Try it »
-- Decrement Decreases the value of a variable by 1 --x Try it »

Assignment Operators

Assignment operators are used to assign values to variables.

In the example below, we use the assignment operator (=) to assign the value 10 to a variable called x:

Example

int x = 10;
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The addition assignment operator (+=) adds a value to a variable:

Example

int x = 10;
x += 5;
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A list of all assignment operators:

Operator Example Same As Try it
= x = 5 x = 5 Try it »
+= x += 3 x = x + 3 Try it »
-= x -= 3 x = x - 3 Try it »
*= x *= 3 x = x * 3 Try it »
/= x /= 3 x = x / 3 Try it »
%= x %= 3 x = x % 3 Try it »
&= x &= 3 x = x & 3 Try it »
|= x |= 3 x = x | 3 Try it »
^= x ^= 3 x = x ^ 3 Try it »
>>= x >>= 3 x = x >> 3 Try it »
<<= x <<= 3 x = x << 3 Try it »

Comparison Operators

Comparison operators are used to compare two values.

Note: The return value of a comparison is either true (1) or false (0).

In the following example, we use the greater than operator (>) to find out if 5 is greater than 3:

Example

int x = 5;
int y = 3;
printf("%d", x > y); // returns 1 (true) because 5 is greater than 3
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A list of all comparison operators:

Operator Name Example Try it
== Equal to x == y Try it »
!= Not equal x != y Try it »
> Greater than x > y Try it »
< Less than x < y Try it »
>= Greater than or equal to x >= y Try it »
<= Less than or equal to x <= y Try it »

Logical Operators

Logical operators are used to determine the logic between variables or values:

Operator Name Description Example Try it
&&  Logical and Returns true if both statements are true x < 5 &&  x < 10 Try it »
||  Logical or Returns true if one of the statements is true x < 5 || x < 4 Try it »
! Logical not Reverse the result, returns false if the result is true !(x < 5 && x < 10) Try it »

Sizeof Operator

The memory size (in bytes) of a data type or a variable can be found with the sizeof operator:

Example

int myInt;
float myFloat;
double myDouble;
char myChar;

printf("%lu\n", sizeof(myInt));
printf("%lu\n", sizeof(myFloat));
printf("%lu\n", sizeof(myDouble));
printf("%lu\n", sizeof(myChar));
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Note that we use the %lu format specifer to print the result, instead of %d. It is because the compiler expects the sizeof operator to return a long unsigned int (%lu), instead of int (%d). On some computers it might work with %d, but it is safer to use %lu.


C Exercises

Test Yourself With Exercises

Exercise:

Fill in the blanks to multiply 10 with 5, and print the result:

int x = 10;
int y = 5;
printf("", x  y);

Start the Exercise