Geethaa SrinivasanIt is a symbol that tells the compiler to perform specific mathematical and logical manipulations. The Operators in C are defined as the part of the mathematical expression which is of various types each discussed in detail in this article.
Arithmetic Operators in C
| Operators | Description | Examples A=10,B=2 |
|---|---|---|
| + | Addition | A+B=>10+2=12 |
| – | Subtraction | A-B=>10-2=8 |
| * | Multiplication | A*B=>10*2=20 |
| / | Division | A/B=>10/2=5 |
| % | The modulo operator gives the remainder of the division | A%B=>10%2=0 |
| ++ | Unary increment | A++=>10++=11 |
| — | Unary decrement | A–=9 |
Example 1:
Explanation:
2*((i/5)+(4*(j-3))%(i+j-2))
step1: 2*(1 + 4 * 2 % 11)
step2: 2*(1 + 8 % 11)
step3: 2*(1+8)
step4: 2*9
step5: 18
The expression is evaluated based on the operator’s precedence.
(), *, /, % is the order of the operators.
In the second printf statement, k++ is the post-increment, k– is the post decrement, it first prints the value then it is incremented or decremented. Whereas in the case of pre-increment or pre-decrement, it first increments or decrements then prints the value.
Relational Operators in C
| Operator | Description | Example |
|---|---|---|
| == | if the two operand values are equal, if yes then the condition is True else False | A=10, B=10, A==B condition is True |
| != | In case if the two operands are not equal, if yes then the condition becomes True | A=10, B=10, A!=B condition is False |
| > | Whereas if the left operand is greater than the right, if yes then the condition becomes True | A=12, B=10 then A>B is True |
| < | If the left operand is lesser than the right, then the condition is True | A=12,B=10 then A<B condition is False |
| >= | Basically, if the left operand is either greater than or equal to the right operand then the condition is True | A=12 or 10 and B=10 then both values of A satisfies A>=B, so the condition becomes True |
| <= | In case if the operand is either lesser than or equal to the right operand then the condition is True else False | A=12 and B=10 then A<=B is not satisfied which gives False |
Logical Operators in C
| Operators | Description | Examples |
|---|---|---|
| && | Logical AND, if both x and y is Non zero, then it returns TRUE | X&&Y=False |
| || | Logical OR, if either x or y is Non zero, then it returns TRUE | X||Y=True |
| ! | Logical NOT ,if x is 1 then it returns 0,which is FALSE and if x is 0 then it returns 1 means TRUE | !X=False |
Example 2:
Explanation:
From the operator’s precedence table we can understand the priority of operators in the above expression is
(), !, <, >, >=, ==, &&, ||.
The relational operators just check whether it is zero or non-zero value, if it is a non-zero value then it is considered as 1(True) and zero as 0(False).
k=((x>y)&&(i>=0)) || ((j<5)&&(!c==d))
step1: ((0.005>-0.01) && (8>=0)) || ((5<5) && (!’c’==’d’)) step2: (1 && 1) || (0 && (0==1))
step3: 1 || (0&&0)
step4: 1 || 0
step5: 1
Note(!’c’=! 99(ASCII value of ‘c’=99=>non-zero ‘c’=99=>non-zero, ‘d’=100=>non-zero=>1
Bitwise Operators in C
|
Category |
Description |
Example |
|
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 |
Example 3:
Explanation:
The bitwise operations are done after converting decimal to equivalent binary values
k=((i | j) >>2) ^ ((~i&j) <<3)
k=((36 | 50) >>2) ^ ((~36&50) <<3)
=((0010 0100 | 0011 0010) >>2) ^ ((~0010 0100 & 0011 0010) <<3)
=(0011 0110 >>2) ^ ((1101 1011 & 0011 0010) <<3)
=(0000 1101) ^ (0001 0010 <<3)
=(0000 1101) ^ (1001 0000)
=1001 1101=>157
=157
Assignment Operators in C:
| Operators | Description | Example |
|---|---|---|
| = | Assignment operator that assigns the value of the right operand to the left | If A=10, B=5 then A=B =>A=5, B=5 |
| += | Addition and Assignment operator, it adds both values and assigns to the left operand | A+=B => A=A+B gives A=15 |
| -= | Subtraction and Assignment operator, it subtracts the right operand value from the left and assigned it to the left operand | A-=B =>A=A-B gives A=5 |
| *= | Multiplication and Assignment operator, it multiply both operand values and the result is assigned to the left operand value | A*=B =>A=A*B A=50 |
| /= | Division and Assignment operator, it divides the left operand value with right and assigns it to the left operand | A/=B =>A=A/B A=2 |
| %= | Modulo and Assignment operator, it divides left operand value with right and assigns a reminder to the left operand | A%=B =>A=A%B A=0 |
| <<= | Left shift and Assignment operator | A<<=B =>A=A<<B, A=10, B=2 0000 1010 <<2 =>0010 1000 |
| >>= | Right shift and Assignment operator. | A>>=B =>A=A>>B 0000 1010 >>2 =>0000 0010 |
| &= | Bitwise AND & Assignment operator | A&=B =>A=A&B 0000 1010 & 0000 0010 = 0000 0010=>2 |
| ^= | Bitwise exclusive OR and Assignment operator | A^=B =>A=A^B 0000 1010 ^ 0000 0010= 0000 1000=>8 |
| |= | Bitwise inclusive OR and Assignment operator | A|=B =>A=A|B 0000 1010| 0000 0010= 0000 1010 =>10 |
Example 4:
Explanation:
From the operator precedence, we can understand the order of the operators used in the above example is(), +=, *=
k+=(20/20)
k+=1
k=k+1=>0+1
k=1
i*=(20%1)
i=i*0=>0
Miscellaneous or Special Operators:
|
List of Miscellaneous Operators |
||
|
Operators |
Description |
Example |
|
sizeof() |
This method returns the size of the variable |
int A=10, sizeof(A) returns 2 or 4 based on a 32bit or 64bit processor. |
|
& |
It represents the address of the variable |
A=10, B=&A, the address of A which holds value 10 is stored in
B. |
|
* |
It represents the pointer variable |
*B=> value inside the address =>10 |
|
?: |
Ternary operator or Conditional Operator |
A>B?A:`B if the condition is satisfied returns A else B |
Example 5:
Explanation:
Ternary operator (Condition)? True: False
In the above example, x=10 is > y=3.5 and hence first printf statement is executed.
If the value of x=2 and y=3.5 then condition x>=y is not satisfied, in such case the second statement will be executed.
The sizeof(variable_name) is used to find the size of the variable. In the above example the variable x is integer type, sizeof(x)=>4bytes and y is float type, sizeof(y)=>4 bytes
‘&’-returns the address of the variable and the ‘*’ – pointer to the variable. We will see about these operators in the future while discussing about pointer.
Operator Precedence
An expression may have many operators in combination, the order in which the operator needs to be evaluated is done by using the operator precedence.
Certain operators have high priority over other operators. The operator with high priority is evaluated first followed by others.
|
Category |
Description |
Example |
|
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 |
