数量增减js

let quantity = 10;
quantity += 5; // 增加5
console.log(quantity); // 输出: 15

quantity -= 3; // 减少3
console.log(quantity); // 输出: 12

function adjustQuantity(currentQuantity, change, condition) {
    if (condition) {
        return currentQuantity + change;
    } else {
        return currentQuantity;
    }
}

let newQuantity = adjustQuantity(10, 5, true); // 如果条件为真，则增加5
console.log(newQuantity); // 输出: 15

function batchAdjustQuantities(items, changes) {
    return items.map((item, index) => item + changes[index]);
}

let items = [10, 20, 30];
let changes = [5, -5, 10];
let updatedItems = batchAdjustQuantities(items, changes);
console.log(updatedItems); // 输出: [15, 15, 40]