JavaScript Comparison Operators

Introduction

JavaScript comparison operators are used to compare two values and return a Boolean value (true or false). These operators are essential in controlling the flow of a program, especially in conditional statements like if, while, and for loops.

In this article, you’ll learn everything about JavaScript comparison operators, including types, syntax, examples, real-life use cases, common mistakes, and interview questions.

What are JavaScript Comparison Operators?

JavaScript comparison operators are symbols used to compare two values or variables. The result of a comparison is always a boolean value.

Example:

let result = 10 > 5;
console.log(result); // true

What is the use of the Comparison Operator

There are lots of uses of the comparison operator

1. Help in decision-making
2. Control program flow
3. Validate data
4. Enable conditional logic
5. Are widely used in real-world applications

Types of JavaScript Comparison Operators

1. Equal to (==) Operator

It is used to check if two values are equal after type conversion.

Returns true if the values are equal, otherwise false

10 == "10";     // true (number 10 is coerced to string "10")
20 == 20     // true (number 20 is coerced to number 20)

2. Strict Equal to (===)

Checks if two values are equal without type conversion. Both value and type must be the same.

10 === "10"; // false
10 === 10;   // true

3. Not Equal (!=)

Checks if two values are not equal (with type conversion).

10 != "10"; // false
10 != 10;   // false

4. Strict Not Equal (!==)

Compares two values for inequality without performing type conversion.

10 !== "10"; // true
10 !== 10;   // false

5. Greater Than (>)

Returns true if the left value is greater than the right value.

10 > 5; // true

6. Greater Than or Equal To (>=)

Returns true if the left value is greater than or equal to the right value.

10 >= 10; // true

7. Less Than (<)

Returns true if the left value is less than the right value.

5 < 10; // true

8. Less Than or Equal To (<=)

Returns true if the left value is less than or equal to the right value.

5 <= 5; // true

9. Ternary Operator (?)

A shorthand for an if-else statement. It takes three operands: a condition, a value if true, and a value if false.

const result = (10 > 5) ? "Yes" : "No"; // "Yes"

Difference Between == and ===

Feature	==	===
Type Conversion	Yes	No
Comparison	Value only	Value + Type
Recommended	❌ No	✅ Yes

Example:

console.log(0 == false);  // true
console.log(0 === false); // false

Note: Always prefer === to avoid unexpected results.

Comparing Different Data Types

You will see comparing Different Data types.

1. String Comparison

Strings are compared alphabetically.

Example:

console.log("apple" < "banana"); // true

2. Number and String

String is converted to a number.

Example:

console.log("5" > 3); // true

3. Boolean Comparison

Example:

console.log(true == 1); // true

4. Null and Undefined

console.log(null == undefined); // true
console.log(null === undefined); // false

Real-Life Examples

I will show you some real-life examples.

1. Login Validation

let username = "admin";
let password = "123";

if (username === "admin" && password === "123") {
   console.log("Login Successful");
}

2. Age Verification

let age = 20;

if (age >= 18) {
   console.log("Eligible to vote");
}

3. E-commerce Discount

let price = 1000;

if (price > 500) {
   console.log("Discount applied");
}

JavaScript comparison – Interview Questions

JavaScript comparison – Objective Questions (MCQs)

Conclusion

JavaScript comparison operators are essential for decision-making and controlling program flow.

By understanding how comparison operators work, including type conversion and strict comparison, you can write safer and more predictable JavaScript code.