Logical operators are used to combine multiple conditions in JavaScript. They help programs make decisions based on more than one rule at the same time.
For example, a user may be allowed to log in only if the username is correct AND the password is correct. Logical operators make this type of decision possible.
Understanding logical operators is essential for writing powerful and flexible conditions in real-world applications.
Types of Logical Operators in JavaScript
&& AND – returns true if both conditions are true
|| OR – returns true if at least one condition is true
! NOT – reverses the result of a condition
These operators are commonly used in authentication systems, form validation, and access control.
This example uses the AND operator. The message is shown only when both conditions are true.
If either the username or password is incorrect, the condition becomes false.
Here, the OR operator checks if at least one condition is true. Since hasPhone is true, the message is displayed.
This logic is often used in account recovery and support systems.
This example shows how the NOT operator reverses a condition. When isBlocked is false, !isBlocked becomes true.
By mastering logical operators, students can build complex decision-making logic and create smarter, more secure applications.