js 自定义方法 可选参数

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

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

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

console.log(sum(1, 2, 3));     // 输出: 6
console.log(sum(4, 5));        // 输出: 9
console.log(sum());            // 输出: 0

function printPersonInfo({ name = 'Unknown', age = 0 } = {}) {
  console.log(`Name: ${name}, Age: ${age}`);
}

printPersonInfo();             // 输出: Name: Unknown, Age: 0
printPersonInfo({ name: 'Bob' }); // 输出: Name: Bob, Age: 0
printPersonInfo({ age: 30 });    // 输出: Name: Unknown, Age: 30
printPersonInfo({ name: 'Alice', age: 25 }); // 输出: Name: Alice, Age: 25