Operators are symbols that perform operations on variables and values. For example, `+`

is an operator used for addition, while `-`

is an operator used for subtraction.

Operators in C++ can be classified into 6 types:

- Arithmetic Operators
- Assignment Operators
- Relational Operators
- Logical Operators
- Bitwise Operators
- Other Operators

## 1. C++ Arithmetic Operators

Arithmetic operators are used to perform arithmetic operations on variables and data. For example,

```
a + b;
```

Here, the `+`

operator is used to add two variables `a` and `b`. Similarly there are various other arithmetic operators in C++.

Operator | Operation |
---|---|

`+` |
Addition |

`-` |
Subtraction |

`*` |
Multiplication |

`/` |
Division |

`%` |
Modulo Operation (Remainder after division) |

### Example 1: Arithmetic Operators

```
#include <iostream>
using namespace std;
int main() {
int a, b;
a = 7;
b = 2;
// printing the sum of a and b
cout << "a + b = " << (a + b) << endl;
// printing the difference of a and b
cout << "a - b = " << (a - b) << endl;
// printing the product of a and b
cout << "a * b = " << (a * b) << endl;
// printing the division of a by b
cout << "a / b = " << (a / b) << endl;
// printing the modulo of a by b
cout << "a % b = " << (a % b) << endl;
return 0;
}
```

**Output**

a + b = 9 a - b = 5 a * b = 14 a / b = 3 a % b = 1

Here, the operators `+`

, `-`

and `*`

compute addition, subtraction, and multiplication respectively as we might have expected.

**/ Division Operator**

Note the operation `(a / b)`

in our program. The `/`

operator is the division operator.

As we can see from the above example, if an integer is divided by another integer, we will get the quotient. However, if either divisor or dividend is a floating-point number, we will get the result in decimals.

In C++, 7/2 is 3 7.0 / 2 is 3.5 7 / 2.0 is 3.5 7.0 / 2.0 is 3.5

**% Modulo Operator**

The modulo operator `%`

computes the remainder. When `a = 9`

is divided by `b = 4`

, the remainder is **1**.

**Note:** The `%`

operator can only be used with integers.

### Increment and Decrement Operators

C++ also provides increment and decrement operators: `++`

and `--`

respectively. `++`

increases the value of the operand by **1**, while `--`

decreases it by **1**.

For example,

```
int num = 5;
// increasing num by 1
++num;
```

Here, the value of `num` gets increased to **6** from its initial value of **5**.

### Example 2: Increment and Decrement Operators

```
// Working of increment and decrement operators
#include <iostream>
using namespace std;
int main() {
int a = 10, b = 100, result_a, result_b;
// incrementing a by 1 and storing the result in result_a
result_a = ++a;
cout << "result_a = " << result_a << endl;
// decrementing b by 1 and storing the result in result_b
result_b = --b;
cout << "result_b = " << result_b << endl;
return 0;
}
```

**Output**

result_a = 11 result_b = 99

In the above program, we used `++`

and `--`

operator as **prefixes**. We can also use these operators as **postfix**.

There is a slight difference when these operators are used as a prefix versus when they are used as a postfix.

To learn more about these operators, visit increment and decrement operators.

## 2. C++ Assignment Operators

In C++, assignment operators are used to assign values to variables. For example,

```
// assign 5 to a
a = 5;
```

Here, we have assigned a value of `5`

to the variable `a`.

Operator | Example | Equivalent to |
---|---|---|

`=` |
`a = b;` |
`a = b;` |

`+=` |
`a += b;` |
`a = a + b;` |

`-=` |
`a -= b;` |
`a = a - b;` |

`*=` |
`a *= b;` |
`a = a * b;` |

`/=` |
`a /= b;` |
`a = a / b;` |

`%=` |
`a %= b;` |
`a = a % b;` |

### Example 2: Assignment Operators

```
#include <iostream>
using namespace std;
int main() {
int a, b, temp;
// 2 is assigned to a
a = 2;
// 7 is assigned to b
b = 7;
// value of a is assigned to temp
temp = a; // temp will be 2
cout << "temp = " << temp << endl;
// assigning the sum of a and b to a
a += b; // a = a +b
cout << "a = " << a << endl;
return 0;
}
```

**Output**

temp = 2 a = 9

## 3. C++ Relational Operators

A relational operator is used to check the relationship between two operands. For example,

```
// checks if a is greater than b
a > b;
```

Here, `>`

is a relational operator. It checks if `a` is greater than `b` or not.

If the relation is **true**, it returns **1** whereas if the relation is **false**, it returns **0**.

Operator | Meaning | Example |
---|---|---|

`==` |
Is Equal To | `3 == 5` gives us false |

`!=` |
Not Equal To | `3 != 5` gives us true |

`>` |
Greater Than | `3 > 5` gives us false |

`<` |
Less Than | `3 < 5` gives us true |

`>=` |
Greater Than or Equal To | `3 >= 5` give us false |

`<=` |
Less Than or Equal To | `3 <= 5` gives us true |

### Example 4: Relational Operators

```
#include <iostream>
using namespace std;
int main() {
int a, b;
a = 3;
b = 5;
bool result;
result = (a == b); // false
cout << "3 == 5 is " << result << endl;
result = (a != b); // true
cout << "3 != 5 is " << result << endl;
result = a > b; // false
cout << "3 > 5 is " << result << endl;
result = a < b; // true
cout << "3 < 5 is " << result << endl;
result = a >= b; // false
cout << "3 >= 5 is " << result << endl;
result = a <= b; // true
cout << "3 <= 5 is " << result << endl;
return 0;
}
```

**Output**

3 == 5 is 0 3 != 5 is 1 3 > 5 is 0 3 < 5 is 1 3 >= 5 is 0 3 <= 5 is 1

**Note**: Relational operators are used in decision making and loops.

## 4. C++ Logical Operators

Logical operators are used to check whether an expression is **true** or **false**. If the expression is **true**, it returns **1** whereas if the expression is **false**, it returns **0**.

Operator | Example | Meaning |
---|---|---|

`&&` |
expression1 && expression2 |
Logical AND. True only if all the operands are true. |

`||` |
expression1 || expression2 |
Logical OR. True if at least one of the operands is true. |

`!` |
!expression |
Logical NOT. True only if the operand is false. |

In C++, logical operators are commonly used in decision making. To further understand the logical operators, let's see the following examples,

```
Suppose,
a = 5
b = 8
Then,
(a > 3) && (b > 5) evaluates to true
(a > 3) && (b < 5) evaluates to false
(a > 3) || (b > 5) evaluates to true
(a > 3) || (b < 5) evaluates to true
(a < 3) || (b < 5) evaluates to false
!(a == 3) evaluates to true
!(a > 3) evaluates to false
```

### Example 5: Logical Operators

```
#include <iostream>
using namespace std;
int main() {
bool result;
result = (3 != 5) && (3 < 5); // true
cout << "(3 != 5) && (3 < 5) is " << result << endl;
result = (3 == 5) && (3 < 5); // false
cout << "(3 == 5) && (3 < 5) is " << result << endl;
result = (3 == 5) && (3 > 5); // false
cout << "(3 == 5) && (3 > 5) is " << result << endl;
result = (3 != 5) || (3 < 5); // true
cout << "(3 != 5) || (3 < 5) is " << result << endl;
result = (3 != 5) || (3 > 5); // true
cout << "(3 != 5) || (3 > 5) is " << result << endl;
result = (3 == 5) || (3 > 5); // false
cout << "(3 == 5) || (3 > 5) is " << result << endl;
result = !(5 == 2); // true
cout << "!(5 == 2) is " << result << endl;
result = !(5 == 5); // false
cout << "!(5 == 5) is " << result << endl;
return 0;
}
```

**Output**

(3 != 5) && (3 < 5) is 1 (3 == 5) && (3 < 5) is 0 (3 == 5) && (3 > 5) is 0 (3 != 5) || (3 < 5) is 1 (3 != 5) || (3 > 5) is 1 (3 == 5) || (3 < 5) is 0 !(5 == 2) is 1 !(5 == 5) is 0

**Explanation of logical operator program**

`(3 != 5) && (3 < 5)`

evaluates to**1**because both operands`(3 != 5)`

and`(3 < 5)`

are**1**(true).`(3 == 5) && (3 < 5)`

evaluates to**0**because the operand`(3 == 5)`

is**0**(false).`(3 == 5) && (3 > 5)`

evaluates to**0**because both operands`(3 == 5)`

and`(3 > 5)`

are**0**(false).`(3 != 5) || (3 < 5)`

evaluates to**1**because both operands`(3 != 5)`

and`(3 < 5)`

are**1**(true).`(3 != 5) || (3 > 5)`

evaluates to**1**because the operand`(3 != 5)`

is**1**(true).`(3 == 5) || (3 > 5)`

evaluates to**0**because both operands`(3 == 5)`

and`(3 > 5)`

are**0**(false).`!(5 == 2)`

evaluates to**1**because the operand`(5 == 2)`

is**0**(false).`!(5 == 5)`

evaluates to**0**because the operand`(5 == 5)`

is**1**(true).

## 5. C++ Bitwise Operators

In C++, bitwise operators are used to perform operations on individual bits. They can only be used alongside `char`

and `int`

data types.

Operator | Description |
---|---|

`&` |
Binary AND |

`|` |
Binary OR |

`^` |
Binary XOR |

`~` |
Binary One's Complement |

`<<` |
Binary Shift Left |

`>>` |
Binary Shift Right |

To learn more, visit C++ bitwise operators.

Apart from the operators discussed above, there are a few other operators, such as `sizeof`

, `?`

, `.`

, `&`

, etc., that cannot be neatly classified into one or another type. We will learn more about these operators in later tutorials.