使用多个可选参数重构JS方法

function greet(name = 'Guest', greeting = 'Hello') {
    return `${greeting}, ${name}!`;
}

console.log(greet()); // 输出: Hello, Guest!
console.log(greet('Alice')); // 输出: Hello, Alice!
console.log(greet('Bob', 'Hi')); // 输出: Hi, Bob!

function sum(...numbers) {
    return numbers.reduce((total, num) => total + num, 0);
}

console.log(sum(1, 2, 3)); // 输出: 6
console.log(sum(5, 10)); // 输出: 15

function createUser({ name, age = 18, email }) {
    return { name, age, email };
}

const user1 = createUser({ name: 'Charlie', email: 'charlie@example.com' });
console.log(user1); // 输出: { name: 'Charlie', age: 18, email: 'charlie@example.com' }

const user2 = createUser({ name: 'David', age: 25, email: 'david@example.com' });
console.log(user2); // 输出: { name: 'David', age: 25, email: 'david@example.com' }

function appendToList(item, list = []) {
    if (!list) list = [];
    list.push(item);
    return list;
}

console.log(appendToList('apple')); // 输出: ['apple']
console.log(appendToList('banana')); // 输出: ['banana'] 而不是 ['apple', 'banana']

function appendToList(item, list = null) {
    if (list === null) list = [];
    list.push(item);
    return list;
}

console.log(appendToList('apple')); // 输出: ['apple']
console.log(appendToList('banana')); // 输出: ['apple', 'banana']