Operator in C++

Relational Operators

In C++, sometimes, we have to compare values to make decisions. This is where relational operators become useful. They help you check how two values relate to each other, like whether one is greater than the other, or if two values are equal.

Let's see a table of all the relational operators:

For example : 

• C

C

#include <iostream>
using namespace std;

int main() {
    int a = 5;
    int b = 3;

    cout << "Equal to: " << (a == b) << endl;  // Output: Equal to: 0 (false)
    cout << "Not equal to: " << (a != b) << endl;  // Output: Not equal to: 1 (true)
    cout << "Greater than: " << (a > b) << endl;  // Output: Greater than: 1 (true)
    cout << "Less than: " << (a < b) << endl;  // Output: Less than: 0 (false)
    cout << "Greater than or equal to: " << (a >= b) << endl;  // Output: Greater than or equal to: 1 (true)
    cout << "Less than or equal to: " << (a <= b) << endl;  // Output: Less than or equal to: 0 (false)

    return 0;
}

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Output

Equal to: 0
Not equal to: 1
Greater than: 1
Less than: 0
Greater than or equal to: 1
Less than or equal to: 0

This code snippet demonstrates how each relational operator is used to compare two integers, a and b. The results are printed to the console, showing which comparisons are true (1) and which are false (0).

Relational operators are crucial for controlling the flow of programs, allowing decisions to be made based on the comparison of values. Whether you're checking if a user's input matches a specific condition or sorting a list of numbers, understanding and using these operators is key.

Logical Operators

Logical operators in C++ are used to combine or invert conditions. They are essential when you need to make decisions based on multiple conditions. There are three main logical operators: AND, OR, and NOT.

The logical operators are:

For example:

• C++

C++

#include <iostream>
using namespace std;

int main() {
    bool condition1 = true;
    bool condition2 = false;

    cout << "AND (both true): " << (condition1 && condition1) << endl;  // Output: AND (both true): 1 (true)
    cout << "AND (one false): " << (condition1 && condition2) << endl;  // Output: AND (one false): 0 (false)
    cout << "OR (one true): " << (condition1 || condition2) << endl;  // Output: OR (one true): 1 (true)
    cout << "OR (both false): " << (condition2 || condition2) << endl;  // Output: OR (both false): 0 (false)
    cout << "NOT (invert true): " << (!condition1) << endl;  // Output: NOT (invert true): 0 (false)
    cout << "NOT (invert false): " << (!condition2) << endl;  // Output: NOT (invert false): 1 (true)

    return 0;
}

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Output

AND (both true): 1
AND (one false): 0
OR (one true): 1
OR (both false): 0
NOT (invert true): 0
NOT (invert false): 1

This code defines two boolean variables, condition, and condition2, and demonstrates each logical operator's effect. For the AND operator, both conditions must be true for the result to be true. For the OR operator, only one of the conditions needs to be true. The NOT operator simply inverts the truth value of a condition.

Bitwise Operators

Bitwise operators in C++ work at the bit level, which is the most basic form of data in computing, represented by 0s and 1s. These operators can perform operations on individual bits of integer data types. Understanding bitwise operators is crucial for low-level programming tasks such as device driver writing or software interfacing with hardware.

The bitwise operators are:

For example : 

• C++

C++

#include <iostream>
using namespace std;

int main() {
    int a = 12; // 1100 in binary
    int b = 5;  // 0101 in binary

    cout << "AND: " << (a & b) << endl;    // Output: AND: 4
    cout << "OR: " << (a | b) << endl;     // Output: OR: 13
    cout << "XOR: " << (a ^ b) << endl;    // Output: XOR: 9
    cout << "NOT: " << (~a) << endl;       // Output: NOT: -13 (for 32-bit int, the actual binary representation will vary)
    cout << "Left Shift: " << (a << 1) << endl; // Output: Left Shift: 24
    cout << "Right Shift: " << (a >> 1) << endl; // Output: Right Shift: 6

    return 0;
}

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Output

AND: 4
OR: 13
XOR: 9
NOT: -13
Left Shift: 24
Right Shift: 6

Assignment Operators

Assignment operators in C++ are used to assign values to variables. The most common assignment operator is =, which you've probably used to set initial values for your variables. But C++ also offers a variety of other assignment operators that combine arithmetic or bitwise operations with assignment. These operators can make your code more concise and easier to read.

The assignment operators are:

For example : 

• C++

C++

#include <iostream>
using namespace std;

int main() {
    int a = 10, b = 12;

    a += 2;  // a is now 12
    a -= 2;  // a is now 10
    a *= 2;  // a is now 20
    a /= 2;  // a is now 10
    a %= 3;  // a is now 1

    b &= 5;  // b is now 4
    b |= 1;  // b is now 5
    b ^= 2;  // b is now 7
    b <<= 1; // b is now 14
    b >>= 1; // b is now 7

    cout << "a: " << a << ", b: " << b << endl;

    return 0;
}

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Output

a: 1, b: 7

This code snippet initializes two variables, a and b, and applies various assignment operators to them. The final values of a and b are printed to demonstrate the effect of each operator.

Assignment operators are a convenient way to perform an operation and assign the result to a variable in a single step. They simplify code and can make complex operations more readable.

Ternary or Conditional Operators

The ternary or conditional operator in C++ is a compact way to write an if-else statement that assigns a value to a variable based on a condition. It's called "ternary" because it takes three operands: a condition, a value to assign if the condition is true, and a value to assign if the condition is false.

The syntax for the ternary operator is: 

condition ? value_if_true : value_if_false;

Example Usage

Let's say you want to assign the larger of two numbers to a variable. You could use an if-else statement, but the ternary operator provides a more concise way to do it:

• C++

C++

#include <iostream>
using namespace std;

int main() {
    int a = 10;
    int b = 20;
    
    // Using ternary operator to assign the larger number to max
    int max = (a > b) ? a : b;

    cout << "The larger number is: " << max << endl;  // Output: The larger number is: 20

    return 0;
}

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Output

The larger number is: 20

In this example, (a > b) is the condition. If it's true (i.e., if a is greater than b), max is assigned the value of a. If it's false, max is assigned the value of b. The ternary operator checks the condition and assigns the appropriate value to max in a single, neat line of code.

The ternary operator is especially useful for simple conditional assignments. It makes your code cleaner and easier to read by eliminating the need for multiple lines of if-else statements for straightforward conditions.

Note-: it's important to use the ternary operator cautiously. For complex conditions or assignments, a regular if-else statement might be more readable and easier to maintain.

Frequently Asked Questions

Can I use the ternary operator for more than just assignment operations?

Yes, the ternary operator can be used anywhere a value is needed, not just for assignments. However, it's most commonly used to assign a value to a variable conditionally. Be mindful of readability when using it in more complex expressions.

How does the modulus operator (%) behave with negative numbers?

The modulus operator (%) returns the remainder of a division operation. When used with negative numbers, the sign of the result is implementation-defined in C++, meaning it could be either positive or negative depending on the compiler. It's best to check your compiler's documentation for specifics.

Are bitwise operators only useful for low-level programming?

While bitwise operators are essential for low-level programming tasks, such as working with device drivers or direct hardware interaction, they also have applications in higher-level programming. They can be used for efficient data manipulation, setting flags, or even certain algorithms that benefit from direct bit manipulation.

What does cout << I << mean?

The expression cout << I; in C++ uses the output stream operator (<<) to send the value of the variable I to the standard output, typically the console.

Conclusion

In this article, we've explored the various types of operators in C++, starting with the basic arithmetic operators that allow us to perform mathematical operations. We then looked into relational operators for comparing values, logical operators for combining conditions, and bitwise operators for manipulating data at the bit level. We also discussed assignment operators, which are crucial for setting and updating variable values, and in the end we talked about ternary or conditional operator for concise conditional assignments.

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