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
These are the operators used to perform arithmetic/mathematical operations on operands. Examples: (+, -, *, /, %,++,–). The arithmetic operator is of two types:
- Unary Operators: Operators that operate or work with a single operand are unary operators. For example: (++ , –)
- Binary Operators: Operators that operate or work with two operands are binary operators. For example: (+ , – , * , /)
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 |
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 equal or 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. |
Logical Operators
The 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 operands is non-zero, then the condition becomes true. | (A || B) is 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. |
Bitwise Operators
Bitwise operator works on bits and perform bit-by-bit operation. The truth tables 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 One’s Complement Operator is unary and has the effect of ‘flipping’ bits. | (~A ) = ~(60), i.e,. -0111101 |
| << | 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 |
Assignment Operators
The following table 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 assign 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 |
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 |