OPERATORS,Arithmetic Operators

OPERATORS

An operator is a symbol that tells the compiler to perform specific mathematical
or logical functions. C language is rich in built-in operators and provides the
following types of operators:
· Arithmetic Operators
· Relational Operators
· Logical Operators
· Bitwise Operators
· Assignment Operators
· Misc Operators
We will, in this chapter, look into the way each operator works.

Arithmetic Operators

The following table shows all the arithmetic operators supported by the C
language. Assume variable A holds 10 and variable B holds 20, then:

Operator Description Example +          Adds two operands.                                                 A + B = 30 -           Subtracts second operand from the first.            A - B = -10 *          Multiplies both operands.                                      A * B = 200 /          Divides numerator by de-numerator.                   B / A = 2 %         Modulus Operator and remainder of after an              integer division.                                                      B % A = 0 ++       Increment operator increases the integer value              by one.                                                                       A++ = 11 -- Decrement operator decreases the integer value by one. A-- = 9

PERATORS

Example
Try the following example to understand all the arithmetic operators available in
C:

#include <stdio.h> main() { int a = 21; int b = 10; int c ; c = a + b; printf("Line 1 - Value of c is %d\n", c ); c = a - b; printf("Line 2 - Value of c is %d\n", c ); c = a * b; printf("Line 3 - Value of c is %d\n", c ); c = a / b; printf("Line 4 - Value of c is %d\n", c ); c = a % b; printf("Line 5 - Value of c is %d\n", c ); c = a++; printf("Line 6 - Value of c is %d\n", c ); c = a--; printf("Line 7 - Value of c is %d\n", c ); }

When you compile and execute the above program, it produces the following
result:

Line 1 - Value of c is 31 Line 2 - Value of c is 11 Line 3 - Value of c is 210 Line 4 - Value of c is 2 Line 5 - Value of c is 1 Line 6 - Value of c is 21 Line 7 - Value of c is 22

Relational Operators

The following table shows all the relational operators supported by C. Assume
variable A holds 10 and variable B holds 20, then:
Operator                             Description                                                           Example
==                   Checks if the values of two operands are equalor not. If yes, then the condition becomes
true.
(A == B) is not
true.
!= Checks if the values of two operands are equal
or not. If the values are not equal, then the
condition becomes true.
(A != B) is true.
> Checks if the value of left operand is greater
than the value of right operand. If yes, then
the condition becomes true.
(A > B) is not
true.
< Checks if the value of left operand is less than
the value of right operand. If yes, then the
condition becomes true.
(A < B) is true.
>= Checks if the value of left operand is greater
than or equal to the value of right operand. If
yes, then the condition becomes true.
(A >= B) is not
true.
<= Checks if the value of left operand is less than
or equal to the value of right operand. If yes,
then the condition becomes true.
(A <= B) is true.

Example
Try the following example to understand all the relational operators available in
C:

#include <stdio.h> main() { int a = 21; int b = 10; int c ; if( a == b ) { printf("Line 1 - a is equal to b\n" ); } else { printf("Line 1 - a is not equal to b\n" ); } if ( a < b ) { printf("Line 2 - a is less than b\n" ); } else { printf("Line 2 - a is not less than b\n" ); } if ( a > b ) { printf("Line 3 - a is greater than b\n" ); } else { printf("Line 3 - a is not greater than b\n" ); } /* Lets change value of a and b */ a = 5; b = 20; if ( a <= b ) { printf("Line 4 - a is either less than or equal to b\n" ); } if ( b >= a ) { printf("Line 5 - b is either greater than or equal to b\n" ); } }

When you compile and execute the above program, it produces the following
result:

Line 1 - a is not equal to b Line 2 - a is not less than b Line 3 - a is greater than b Line 4 - a is either less than or equal to b Line 5 - b is either greater than or equal to b

Logical Operators

Following table shows all the logical operators supported by C language. Assume
variable A holds 1 and variable B holds 0, then:

Operator Description Example

&& Called Logical AND operator. If both the
operands are non-zero, then the condition
becomes true.
(A && B) is
false.
|| Called Logical OR Operator. If any of the two (A || B) is true.

operands is non-zero, then the condition
becomes true.
! Called Logical NOT Operator. It is used to
reverse the logical state of its operand. If a
condition is true, then Logical NOT operator will
make it false.
!(A && B) is
true.
Example
Try the following example to understand all the logical operators available in C:
When you compile and execute the above program, it produces the following.

#include <stdio.h> main() { int a = 5; int b = 20; int c ; if ( a && b ) { printf("Line 1 - Condition is true\n" ); } if ( a || b ) { printf("Line 2 - Condition is true\n" ); } /* lets change the value of a and b */ a = 0; b = 10; if ( a && b ) { printf("Line 3 - Condition is true\n" ); } else { printf("Line 3 - Condition is not true\n" ); } if ( !(a && b) ) { printf("Line 4 - Condition is true\n" ); } }

result:

Line 1 - Condition is true Line 2 - Condition is true Line 3 - Condition is not true Line 4 - Condition is true

Bitwise Operators

Bitwise operators work on bits and perform bit-by-bit operation. The truth table
for &, |, and ^ is as follows:
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
Assume A = 60 and B = 13; in binary format, they will be as follows:
A = 0011 1100
B = 0000 1101
-----------------
A&B = 0000 1100
A|B = 0011 1101
A^B = 0011 0001
~A = 1100 0011
The following table lists the bitwise operators supported by C. Assume variable
‘A’ holds 60 and variable ‘B’ holds 13, then:

Operator Description Example

& Binary AND Operator copies a bit to the result
if it exists in both operands.
(A & B) = 12, i.e.,
0000 1100
| Binary OR Operator copies a bit if it exists in
either operand.
(A | B) = 61, i.e.,
0011 1101
^ Binary XOR Operator copies the bit if it is set
in one operand but not both.
(A ^ B) = 49, i.e.,
0011 0001
~ Binary Ones Complement Operator is unary
and has the effect of 'flipping' bits.
(~A ) = -61, i.e.,
1100 0011 in 2's
complement form.
<< Binary Left Shift Operator. The left operands
value is moved left by the number of bits
specified by the right operand.
A << 2 = 240,
i.e., 1111 0000
>> Binary Right Shift Operator. The left operands
value is moved right by the number of bits
specified by the right operand.
A >> 2 = 15, i.e.,
0000 1111
Example
Try the following example to understand all the bitwise operators available in C:

#include <stdio.h> main() { unsigned int a = 60; /* 60 = 0011 1100 */ unsigned int b = 13; /* 13 = 0000 1101 */ int c = 0; c = a & b; /* 12 = 0000 1100 */ printf("Line 1 - Value of c is %d\n", c ); c = a | b; /* 61 = 0011 1101 */ printf("Line 2 - Value of c is %d\n", c ); c = a ^ b; /* 49 = 0011 0001 */ printf("Line 3 - Value of c is %d\n", c ); c = ~a; /*-61 = 1100 0011 */ printf("Line 4 - Value of c is %d\n", c ); c = a << 2; /* 240 = 1111 0000 */ printf("Line 5 - Value of c is %d\n", c ); c = a >> 2; /* 15 = 0000 1111 */ printf("Line 6 - Value of c is %d\n", c ); }

When you compile and execute the above program, it produces the following
result:

Line 1 - Value of c is 12 Line 2 - Value of c is 61 Line 3 - Value of c is 49 Line 4 - Value of c is -61 Line 5 - Value of c is 240 Line 6 - Value of c is 15

Assignment Operators

The following tables lists the assignment operators supported by the C language:
Operator Description Example
= Simple assignment operator. Assigns
values from right side operands to left
side operand.
C = A + B will assign
the value of A + B to
C
+= Add AND assignment operator. It adds the
right operand to the left operand and
assigns the result to the left operand.
C += A is equivalent
to C = C + A
-= Subtract AND assignment operator. It
subtracts the right operand from the left
operand and assigns the result to the left
operand.
C -= A is equivalent
to C = C - A
*= Multiply AND assignment operator. It
multiplies the right operand with the left
operand and assigns the result to the left
operand.
C *= A is equivalent
to C = C * A
/= Divide AND assignment operator. It
divides the left operand with the right
operand and assigns the result to the left
operand.
C /= A is equivalent
to C = C / A
%= Modulus AND assignment operator. It
takes modulus using two operands and
assigns the result to the left operand.
C %= A is equivalent
to C = C % A
<<= Left shift AND assignment operator. C <<= 2 is same as C
= C << 2
>>= Right shift AND assignment operator. C >>= 2 is same as C
= C >> 2
&= Bitwise AND assignment operator. C &= 2 is same as C
= C & 2
^= Bitwise exclusive OR and assignment
operator.
C ^= 2 is same as C
= C ^ 2
|= Bitwise inclusive OR and assignment
operator.
C |= 2 is same as C =
C | 2

Example
Try the following example to understand all the assignment operators available
in C:

#include <stdio.h> main() { int a = 21; int c ; c = a; printf("Line 1 - = Operator Example, Value of c = %d\n", c ); c += a; printf("Line 2 - += Operator Example, Value of c = %d\n", c ); c -= a; printf("Line 3 - -= Operator Example, Value of c = %d\n", c ); c *= a; printf("Line 4 - *= Operator Example, Value of c = %d\n", c ); c /= a; printf("Line 5 - /= Operator Example, Value of c = %d\n", c ); c = 200; c %= a; printf("Line 6 - %= Operator Example, Value of c = %d\n", c ); c <<= 2; printf("Line 7 - <<= Operator Example, Value of c = %d\n", c ); c >>= 2; printf("Line 8 - >>= Operator Example, Value of c = %d\n", c ); c &= 2; printf("Line 9 - &= Operator Example, Value of c = %d\n", c ); c ^= 2; printf("Line 10 - ^= Operator Example, Value of c = %d\n", c ); c |= 2; printf("Line 11 - |= Operator Example, Value of c = %d\n", c ); }

When you compile and execute the above program, it produces the following
result:

Line 1 - = Operator Example, Value of c = 21 Line 2 - += Operator Example, Value of c = 42 Line 3 - -= Operator Example, Value of c = 21 Line 4 - *= Operator Example, Value of c = 441 Line 5 - /= Operator Example, Value of c = 21 Line 6 - %= Operator Example, Value of c = 11 Line 7 - <<= Operator Example, Value of c = 44 Line 8 - >>= Operator Example, Value of c = 11 Line 9 - &= Operator Example, Value of c = 2 Line 10 - ^= Operator Example, Value of c = 0 Line 11 - |= Operator Example, Value of c = 2

Misc Operators↦sizeof & ternary

Besides the operators discussed above, there are a few other important
operators including sizeof and ? : supported by the C Language.
Operator Description Example
sizeof() Returns the size of a variable. sizeof(a), where a is
integer, will return 4.
& Returns the address of a variable. &a; returns the actual
address of the
variable.
* Pointer to a variable. *a;
? : Conditional Expression. If Condition is true ?
then value X :
otherwise value Y
Example
Try following example to understand all the miscellaneous operators available in
C:

#include <stdio.h> main() { int a = 4; short b; double c; int* ptr; /* example of sizeof operator */ printf("Line 1 - Size of variable a = %d\n", sizeof(a) ); printf("Line 2 - Size of variable b = %d\n", sizeof(b) ); printf("Line 3 - Size of variable c= %d\n", sizeof(c) ); /* example of & and * operators */ ptr = &a; /* 'ptr' now contains the address of 'a'*/ printf("value of a is %d\n", a); printf("*ptr is %d.\n", *ptr); /* example of ternary operator */ a = 10; b = (a == 1) ? 20: 30; printf( "Value of b is %d\n", b ); b = (a == 10) ? 20: 30; printf( "Value of b is %d\n", b ); }

When you compile and execute the above program, it produces the following
result:

value of a is 4 *ptr is 4. Value of b is 30 Value of b is 20