Operators in C++

Operators are mainly considered the foundation of any programming language. Operators are symbols that enable us to carry out particular logical and mathematical operations on operands. In other words, an operator controls the operands. For example, the operator '+' is used for addition, as shown below:

c = a + b;

Here, "a" and "b" are the operands, and "+" is the operator, also known as the addition operator. The addition operator tells the compiler to combine which means to add the operands 'a' and 'b’.

In this tutorial,  with the help of some examples, we will learn about the different types of operators in C++. An operator is a symbol in programming that performs an operation on a value or variable.

Operators are symbols that operate on variables and values. For example, + is an addition operator, whereas - is a subtraction operator.
 

C++ Operands and Operators

C++ operators are mainly classified into six types:

Arithmetic Operators in C++

To perform arithmetic operations on variables and data, arithmetic operators are used. As an example,

a + b
 

The + operator is used in order to add two variables, a and b. In C++, there are numerous other arithmetic operators.

#include <iostream>
using namespace std;

int main() {
    int a, b;
    a = 5;
    b = 2;

    // here  printing of the sum of a and b takes place
    cout << "a + b = " << (a + b) << endl;

    //  difference of a and b is printing
    cout << "a - b = " << (a - b) << endl;

    //  the product of a and b is printing
    cout << "a * b = " << (a * b) << endl;

    // the division of a by b is printing
    cout << "a / b = " << (a / b) << endl;

    // the modulo of a by b is printing
    cout << "a % b = " << (a % b) << endl;

    return 0;
}

Output:

a + b = 7
a - b = 3
a * b = 10
a / b = 2
a % b = 1

As expected, the operators +, -, and * compute addition, subtraction, and multiplication, respectively.

The Division operator (/)

In our program, take note of the operation (a / b). The division operator is the / operator.

As shown in the preceding example, by dividing an integer by another integer then we will be getting the quotient. However, if either the divisor or the dividend is a floating-point number, the result will be in decimals.

The Modulo operator (%)

The remainder is computed using the modulo operator %. The remainder is 1 when a = 9 is divided by b = 4.

Increment and Decrement Operators (Unary operators)

Unary operators are those that operate or work with a single operand. As an example: Decrement(--) and Increment(++)  Operators

That is the increment and decrement operators in C++ are ++ and --, respectively.
 
++ increases the operand's value by 1 and -- decreases it by 1.

For an example

int num = 6;

// increment operator
++num;  // 7
 

The code ++num; here increases the value of num by 1.

//An example of the working of increment and decrement operators

#include <iostream>
using namespace std;

int main() {
    int a = 20, b = 200, result_a, result_b;

    // here we are incrementing a by 1 and we will store the result in result_a
    result_a = ++a;
    cout << "result_a = " << result_a << endl;


    //here we are  decrementing b by 1 and we will store the result in result_b   
    result_b = --b;
    cout << "result_b = " << result_b << endl;

    return 0;
}

Output:

result_a = 21
result_b = 199

The ++ and -- operators were used as prefixes in the preceding program (++a and —b). However, these operators can also be used as postfixes (a++ and b--).

Assignment Operators in C++

Assignment operators are used in C++ to assign values to variables.

For example,

// assign 10 to b
b = 10;
 

The variable b has been assigned a value of 10 in the above example.

//An example for the assignment operators

#include <iostream>
using namespace std;

int main() {
    int a, b;

    // here the 6 is assigned to a
    a = 6;

    // here the 12 is assigned to b
    b = 12;

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

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

    return 0;
}

Output:

a = 6
b = 12

After a += b;
a = 18

Relational Operators in C++

To check the relationship between two operands, a relational operator is used. For example,

// check whether a is greater than b
a > b;

 

In this case, > is a relational operator. It helps to check whether a is greater than b.

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

#include <iostream>
using namespace std;

int main() {
    int a, b;
    a = 5;
    b = 7;
    bool result;

    result = (a == b);   // false
    cout << "5 == 7 is " << result << endl;

    result = (a != b);  // true
    cout << "5 != 7 is " << result << endl;

    result = a > b;   // false
    cout << "5 > 7 is " << result << endl;

    result = a < b;   // true
    cout << "5 < 7 is " << result << endl;

    result = a >= b;  // false
    cout << "5 >= 7 is " << result << endl;

    result = a <= b;  // true
    cout << "5 <= 7 is " << result << endl;

    return 0;
}

Output:

5 == 7 is 0
5 != 7 is 1
5 > 7 is 0
5 < 7 is 1
5 >= 7 is 0
5 <= 7 is 1

Logical Operators in C++

Logical operators are often used to check whether an expression is true or false. If the expression is true, it will return 1, and if it is false, then it returns 0.

Logical operators are commonly used for decision-making in C++. Let's look at some examples to fully understand the logical operators.

#include <iostream>
using namespace std;

int main()
{
    bool result;
    int a = 4, b = 6;

    result = (a != b) && (a < b);    // true
    cout << "(a != b) && (a < b) is " << result << endl;

    result = (a == b) && (a < b);    // false
    cout << "(a == b) && (a < b) is " << result << endl;

    result = (a == b) && (a > b);    // false
    cout << "(a == b) && (a > b) is " << result << endl;

    result = (a != b) || (a < b);    // true
    cout << "(a != b) || (a < b) is " << result << endl;

    result = (a != b) || (a > b);    // true
    cout << "(a != b) || (a > b) is " << result << endl;

    result = (a == b) || (a > b);    // false
    cout << "(a == b) || (a > b) is " << result << endl;

    result = !(b == 3);    // true
    cout << "!(b == 3) is " << result << endl;

    result = !(b == b);    // false
    cout << "!(b == b) is " << result << endl;

    return 0;
}

Output:

(a != b) && (a < b) is 1
(a == b) && (a < b) is 0
(a == b) && (a > b) is 0
(a != b) || (a < b) is 1
(a != b) || (a > b) is 1
(a == b) || (a > b) is 0
!(b == 3) is 1
!(b == b) is 0

Logic operator program explanation

• (4 != 6) && (4 < 6) is 1 this is because here both the operands are true
• (4 == 6) && (4 < 6) is 0 this is because the operand 4==6 is false(0)
• (4 == 6) && (4 > 6) is 0 this is because here the two operands ( 4==6 and 4>6) are false.
• (4 != 6) || (4 < 6) is 1 this is because here both operands are true hence (4 != 6) || (4 < 6) is true(1)
• (4 != 6) || (4 > 6) is 1 this is because here at least one operand (4 != 6) is true hence (4 != 6) || (4 > 6) is true(1)
• (4 == 6) || (4 > 6) is 0 this is because here both given operands are false.
• !(6 == 3) is 1 this is because the operand (6==3) is false (0)
• !(6 == 6) is 0 this is because the operand (6==6) is true (1)

Bitwise Operators in C++

Bitwise operators in C++ operate on integer data at the individual bit level. These operations include bit testing, bit setting, and bit shifting.  A detailed explanation of bitwise operators in C++ is given in the next tutorial. 

Other Operators in C++

Here is a list of some other common C++ operators. Subsequent tutorials will cover them in detail.