Logical Operators in C

🎙️ Introduction

Hello everyone!

In the previous chapter, we learned about Relational Operators.

We saw how they compare two values and return either true or false.

But now think about this:

👉 What if we need to check more than one condition?
👉 What if a student must pass both Math and Science?
👉 What if a person must be above 18 AND a citizen to vote?

To solve such problems, we use Logical Operators...Read More

🔹 Step 1: What Are Logical Operators?

Logical operators are used to combine two or more conditions.

They work on boolean expressions and return:

True (1)
OR

False (0)

In simple words:

👉 Logical operators help us build complex decision...Read More

🔹 Step 2: Types of Logical Operators in C

C language provides three logical operators:

1️⃣ Logical AND (&&)
2️⃣ Logical OR (||)
3️⃣ Logical NOT (!)

Let us understand each one carefully...Read More

🔹 Step 3: Logical AND (&&)

The AND operator checks whether both conditions are true.

If both conditions are true → Result is true.
If even one condition is false → Result is false.

Example concept:

If marks >= 40 AND attendance >= 75
Then student passes.

Truth Table for AND:

True && True → True

True && False → False...Read More

🔹 Step 4: Logical OR (||)

The OR operator checks whether at least one condition is true.

If any one condition is true → Result is true.
If both conditions are false → Result is false.

Example concept:

If student has sports quota OR academic quota
Then allow admission.

Truth Table for OR:

True || True → True

True || False → True...Read More.

🔹 Step 5: Logical NOT (!)

The NOT operator reverses the result of a condition.

If condition is true → NOT makes it false.
If condition is false → NOT makes it true.

Example concept:

If !isLoggedIn
Then show login page.

It simply changes true to false and false to true...Read More

🔹 Step 6: How Logical Operators Work with Relational Operators

Logical operators are usually combined with relational operators.

Example concept:

If (marks >= 40) && (attendance >= 75)

Here:

Relational operators compare values.

Logical operator combines conditions...Read More

🔹 Step 7: Short-Circuit Behavior

C language uses short-circuit evaluation.

For AND (&&):
If first condition is false, second condition is not checked.

For OR (||):
If first condition is true, second condition is...Read More

🔹 Step 8: Real-Life Example

Imagine a job application system.

Condition to apply:

Age >= 21
AND

Degree completed

If both conditions are true → Eligible.

Another example:

Emergency access allowed if...Read More

📌 Summary

In this chapter, we learned:

Logical operators combine multiple conditions.

C provides three logical operators:

&& (AND) → Both conditions must be true

|| (OR) → At least one condition must be true...Read More