 # C++ Operators

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:

## 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
• `--` decreases it by 1

For example,

``````int num = 5;

// increment operator
++num;  // 6``````

Here, the code `++num;` increases the value of num by 1.

### 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 have used the `++` and `--` operators as prefixes (++a and --b). However, we can also use these operators as postfix (a++ and b--).

## 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 3: Assignment Operators

``````#include <iostream>
using namespace std;

int main() {
int a, b;

// 2 is assigned to a
a = 2;

// 7 is assigned to b
b = 7;

cout << "a = " << a << endl;
cout << "b = " << b << endl;
cout << "\nAfter a += b;" << endl;

// assigning the sum of a and b to a
a += b;  // a = a +b
cout << "a = " << a << endl;

return 0;
}``````

Output

```a = 2
b = 7

After a += b;
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

## 6. Other C++ Operators

Here's a list of some other common operators available in C++. We will learn about them in later tutorials.

Operator Description Example
`sizeof` returns the size of data type `sizeof(int); // 4`
`?:` returns value based on the condition `string result = (5 > 0) ? "even" : "odd"; // "even"`
`&` represents memory address of the operand `&num; // address of num`
`.` accesses members of struct variables or class objects `s1.marks = 92;`
`->` used with pointers to access the class or struct variables `ptr->marks = 92;`
`<<` prints the output value `cout << 5;`
`>>` gets the input value `cin >> num;`