Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
What is Multiplication Assignment Operator (*=) in JavaScript?
The multiplication assignment operator (*=) in JavaScript provides a shorthand way to multiply a variable by a value and assign the result back to the variable. Instead of writing a = a * b, you can simply use a *= b.
Syntax
operand1 *= operand2 // equivalent to: operand1 = operand1 * operand2
The multiplication assignment operator is a binary operator that multiplies the left operand by the right operand and stores the result in the left operand.
Example 1: Basic Usage with Numbers
Here's how the multiplication assignment operator works with numeric values:
<!DOCTYPE html>
<html>
<body>
<h2>Multiplication Assignment Operator (*=) in JavaScript</h2>
<p>Enter two numbers:</p>
<input type="number" id="inp1"><br><br>
<input type="number" id="inp2"><br><br>
<button onclick="display()">Show Result</button>
<p id="result"></p>
<script>
function display() {
var inp1 = document.getElementById("inp1");
var inp2 = document.getElementById("inp2");
var val1 = Number(inp1.value);
var val2 = Number(inp2.value);
// Using multiplication assignment operator
val1 *= val2; // equivalent to: val1 = val1 * val2
document.getElementById("result").innerHTML = "<b>Result: " + val1 + "</b>";
}
</script>
</body>
</html>
Example 2: Working with Different Data Types
The multiplication assignment operator handles type conversion automatically when working with strings that contain numeric values:
<!DOCTYPE html>
<html>
<body>
<h2>Multiplication Assignment with Mixed Types</h2>
<p>Enter a number and text:</p>
<input type="number" id="inp1" placeholder="Enter number"><br><br>
<input type="text" id="inp2" placeholder="Enter text or number"><br><br>
<button onclick="calculate()">Calculate</button>
<p id="result"></p>
<script>
function calculate() {
var val1 = Number(document.getElementById("inp1").value);
var val2 = Number(document.getElementById("inp2").value);
val1 *= val2;
document.getElementById("result").innerHTML = "<b>Result: " + val1 + "</b>";
}
</script>
</body>
</html>
How It Works
When using the multiplication assignment operator:
- If both operands are numbers, normal multiplication occurs
- If a string contains a valid number, JavaScript converts it automatically
- If a string contains non-numeric characters, the result will be
NaN(Not a Number) - The operator modifies the original variable, unlike regular multiplication
Common Use Cases
The multiplication assignment operator is commonly used for:
- Scaling values (e.g., converting units)
- Calculating compound interest or growth rates
- Updating counters or accumulators in loops
- Mathematical operations where you need to modify the original variable
Conclusion
The multiplication assignment operator (*=) provides a concise way to multiply and assign values in JavaScript. It handles type conversion automatically but returns NaN when multiplying numbers with non-numeric strings.
713 Views
