What Are Assignment Operators in JavaScript?
Assignment operators in JavaScript are used to assign values to variables. They simplify coding by combining basic operations (like addition or subtraction) with assignment in a single step. These operators are essential for developers to write concise and efficient code.
Types of Assignment Operators in JavaScript
Here’s a list of commonly used assignment operators:
| Operator | Name | Example | Explanation | Result |
|---|---|---|---|---|
= | Assignment Operator | x = 5 | Assigns the value 5 to variable x. | x = 5 |
| += | Add and Assign | x += 3 | Adds 3 to x and assigns the result. | x = x + 3 |
| -= | Subtract and Assign | x -= 2 | Subtracts 2 from x and assigns it. | x = x – 2 |
| *= | Multiply and Assign | x *= 4 | Multiplies x by 4 and assigns it. | x = x * 4 |
| /= | Divide and Assign | x /= 5 | Divides x by 5 and assigns it. | x = x / 5 |
| %= | Modulus and Assign | x %= 3 | Assigns remainder of x / 3 to x. | x = x % 3 |
| **= | Exponent and Assign | x **= 2 | Raises x to the power of 2 and assigns it. | x = x ** 2 |
Using Assignment Operators in Code
1. Basic Assignment (=)
The = operator assigns a value to a variable.
Example:
let num = 10;
console.log(num); // Output: 10
2. Add and Assign (+=)
The += operator adds a value to a variable and assigns the result back.
Example:
let score = 50;
score += 20; // Adds 20 to score
console.log(score); // Output: 70
3. Subtract and Assign (-=)
The -= operator subtracts a value from a variable and assigns the result.
Example:
let balance = 1000;
balance -= 250; // Subtracts 250 from balance
console.log(balance); // Output: 750
4. Multiply and Assign (*=)
The *= operator multiplies a variable by a value and assigns the result.
Example:
let price = 200;
price *= 2; // Multiplies price by 2
console.log(price); // Output: 400
5. Divide and Assign (/=)
The /= operator divides a variable by a value and assigns the result.
Example:
let total = 500;
total /= 5; // Divides total by 5
console.log(total); // Output: 100
6. Modulus and Assign (%=)
The %= operator assigns the remainder of a division.
Example:
let remainder = 10;
remainder %= 3; // Finds remainder when 10 is divided by 3
console.log(remainder); // Output: 1
7. Exponent and Assign (**=)
The **= operator raises a variable to the power of a value and assigns it.
Example:
let base = 3;
base **= 3; // Raises base to the power of 3
console.log(base); // Output: 27
Practical Example: Calculating Discounts
Code Example:
let originalPrice = 500;
let discount = 20; // in percentage
originalPrice -= (originalPrice * discount) / 100; // Apply discount
console.log("Final Price:", originalPrice); // Output: Final Price: 400
Why Are Assignment Operators Important?
Assignment operators simplify code and improve readability. Instead of writing separate statements for operations and assignments, you can combine them, making your code more efficient and easier to maintain.