演示乘法和除法赋值运算符 (*=, /=)
在这一步中,你将探索 JavaScript 中的乘法和除法赋值运算符 *=
和 /=
。这些运算符提供了一种简洁的方式,可以将变量乘以或除以某个值,并将结果赋值回同一个变量。
打开 assignment-operators.html
文件,并在 <script>
标签内添加以下 JavaScript 代码:
// Multiplication assignment operator (*=)
let price = 10;
console.log("Initial Price:", price);
price *= 3; // Equivalent to: price = price * 3
console.log("Price after *3:", price);
// Division assignment operator (/=)
let quantity = 24;
console.log("Initial Quantity:", quantity);
quantity /= 4; // Equivalent to: quantity = quantity / 4
console.log("Quantity after /4:", quantity);
// Practical example: Calculating total cost
let itemPrice = 5;
let itemCount = 7;
console.log("Item Price:", itemPrice);
console.log("Item Count:", itemCount);
let totalCost = itemPrice * itemCount;
console.log("Total Cost:", totalCost);
totalCost *= 0.9; // Apply 10% discount
console.log("Discounted Total Cost:", totalCost);
关于乘法和除法赋值运算符的关键点:
*=
将变量乘以右侧的值并赋值结果
/=
将变量除以右侧的值并赋值结果
- 这些运算符有助于简化数学运算和赋值操作
- 它们适用于数值,并可用于各种计算
浏览器控制台中的示例输出:
Initial Price: 10
Price after *3: 30
Initial Quantity: 24
Quantity after /4: 6
Item Price: 5
Item Count: 7
Total Cost: 35
Discounted Total Cost: 31.5