Operators in C
An operator is a special symbol that tells the compiler to perform specific mathematical or logical operations. It is the combination of constants and variables through expressions. Example:
int c = a+b*5Where, =, +,* are operators, a,b,c are the variables and 5 is the constants. There are various types of the operator in C Language.
Types of Operator
- Arithmetic Operators
- Relational Operators
- Logical Operators
- Bitwise Operators
- Assignment Operators
- Misc Operators
- Increment/Decrement operators
Arithmetic operators are used to perform mathematical calculations like addition, subtraction, multiplication, division, and modulus.
| Operator | Example (int a=9, b=2) | Result |
| + | A+B | 11 |
| - | A-B | 7 |
| * | A*B | 18 |
| / | A/B | 4.5 |
| % | A%4 | 1 |
Example:
#include <stdio.h>
int main()
{
int a=9,b=2, add,sub,mul,div,mod;
add = a+b;
sub = a-b;
mul = a*b;
div = a/b;
mod = a%b;
printf("Addition of (a+b ) is : %d\n", add);
printf("Subtraction of (a-b) is : %d\n", sub);
printf("Multiplication of (a*b) is : %d\n", mul);
printf("Division of (a / b) is : %d\n", div);
printf("Modulus of (a%b) is : %d\n", mod);
}
Output:
Addition of (a+b ) is : 11 Subtraction of (a-b) is : 7 Multiplication of (a*b) is : 18 Division of (a / b) is : 4 Modulus of (a%b) is : 1Relational Operators Relational operators are used to compare the value of two variables.
| Operator | Description |
| > | x > y (x is greater than y) |
| < | x < y (x is less than y) |
| >= | x >= y (x is greater than or equal to y) |
| <= | x <= y (x is less than or equal to y) |
| == | x == y (x is equal to y) |
| != | x != y (x is not equal to y) |
Let us consider an example
#include <stdio.h>
int main()
{
int a=9,b=2;
if (a == b)
{
printf("a and b are equal");
}
else
{
printf("a and b are not equal");
}
}
Output
a and b are not equalLogical Operators
Logical operators are used to perform logical operations on the given two variables. There are 3 logical operators in C LanguageAND(&&), OR ( || ) and NOT (!).
Let us consider an example
| Operator | Description |
| && | It returns true when both conditions are true. |
| || | It returns true while at least one condition is true. |
| ! | It reverses the state of the operand. |
Let us consider an example
#include <stdio.h>
int main()
{
int a=8, b=3, c=10;
if(a>b && b<c){
printf("$$Operator : Both Condition are true \n");
}
if(a>b || b<c){
printf("||Operator : Only one condition is true \n");
}
return 0;
}
Output
$$Operator : Both Condition are true ||Operator : Only one condition is trueAssignment operators
Assignment operators are used to assign the values for the variable.
Let us consider an example
Miscellaneous operators in C
| Operator | Description |
| = | sum = 10; 10 is assigned to variable sum |
| += | sum += 10; This is same as sum = sum + 10 |
| -= | sum -= 10; It is same as sum = sum – 10 |
| *= | sum *= 10; It is same as sum = sum * 10 |
| /= | sum /= 10; It is same as sum = sum / 10 |
| %= | sum %= 10; It is same as sum = sum % 10 |
| &= | sum&=10; It is same as sum = sum & 10 |
| ^= | sum ^= 10; It is same as sum = sum ^ 10 |
Let us consider an example
#include <stdio.h>
int main(){
int a=8,b=3,c;
c=a+b;
printf("a+b value is assign to c");
return 0;
}
Output
a+b value is assign to cOperator Precedence in C The precedence of operators are used to specify the operators which will be evaluated first and next. Example:
int result = 5+5*10-2;The precedence and associatively of C operators is given below:
| Category | Operator | Associativity |
| Postfix | () [] -> . ++ - - | Left to right |
| Unary | + - ! ~ ++ - - (type)* & sizeof | Right to left |
| Multiplicative | * / % | Left to right |
| Additive | + - | Left to right |
| Shift | <<>> | Left to right |
| Relational | <<= >>= | Left to right |
| Equality | == != | Left to right |
| Bitwise AND | & | Left to right |
| Bitwise XOR | ^ | Left to right |
| Bitwise OR | | | Left to right |
| Logical AND | && | Left to right |
| Logical OR | || | Left to right |
| Conditional | ?: | Right to left |
| Assignment | = += -= *= /= %=>>= <<= &= ^= |= | Right to left |
| Comma | , | Left to right |
Miscellaneous operators in C
There are few other important operators including sizeof and ?: supported by C Language.
Bitwise operators
| Operator | Description |
| sizeof() | It returns the size of a variable. |
| & | It returns the address of a variable. |
| * | It assigns pointer to a variable. |
| ? : | It is a Conditional Expression. |
Bitwise operators
Bitwise operator is used to perform bit by bit operations on two variables.
There are following truth table for &, | and ^.
| P | q | p & q | p | q | p ^ q |
| 0 | 0 | 0 | 0 | 0 |
| 0 | 1 | 0 | 1 | 1 |
| 1 | 1 | 1 | 1 | 0 |
| 1 | 0 | 0 | 1 | 1 |
| Operator | Description |
| & Binary AND Operator | It copies a bit to the result if it exists in both operands. |
| | Binary OR Operator | It copies a bit if it exists in either operand. |
| ^ Binary XOR Operator | It copies the bit if it is set in one operand but not both. |
| ~ Binary Ones Complement Operator | It is unary and has the effect of 'flipping' bits. |
| << Binary Left Shift Operator | The left operands value is moved left by the number of bits specified by the right operand. |
| >> Binary Right Shift Operator. | The left operands value is moved right by the number of bits specified by the right operand. |
Increment / decrement operator
Increment Operator:
The increment operator is used to increase the value of the variable by one.
Syntax:
Increment operator: ++ var_name; or var_name++;Example:
Increment operator: ++i; i++;Decrement Operator:
Decrement operator is used to decrease the value of the variable by one.
Syntax:
Decrement operator: -- var_name; or var_name--;Example:
Decrement operator: --i; i--;Difference between Increment & Decrement operators
There are various differences between pre/Post increment & decrement operators in C.
| Operator | Operator/Description |
| Pre increment operator (++i) | The value of i is incremented before assigning it to the variable i. |
| Post increment operator (i++) | The value of i is incremented after assigning it to the variable i. |
| Pre decrement operator (- -i) | The value of i is decremented before assigning it to the variable i. |
| Post decrement operator (i--) | The value of i is decremented after assigning it to variable i. |