js中冒号什么意思

const person = {
  name: "Alice",
  age: 25,
  occupation: "Engineer"
};

switch (day) {
  case 1:
    console.log("Monday");
    break;
  case 2:
    console.log("Tuesday");
    break;
  default:
    console.log("Other day");
}

const age = 18;
const canVote = (age >= 18) ? "Yes" : "No";
console.log(canVote); // 输出: Yes

function greet(name = "Guest") {
  console.log(`Hello, ${name}!`);
}
greet(); // 输出: Hello, Guest!
greet("Alice"); // 输出: Hello, Alice!

class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  greet() {
    console.log(`Hello, my name is ${this.name}`);
  }
}

outerLoop: for (let i = 0; i < 3; i++) {
  innerLoop: for (let j = 0; j < 3; j++) {
    if (i === 1 && j === 1) {
      break outerLoop;
    }
    console.log(`i: ${i}, j: ${j}`);
  }
}

/**
 * @param {string} name - The name of the person.
 * @param {number} age - The age of the person.
 */
function greet(name, age) {
  console.log(`Hello, ${name}! You are ${age} years old.`);
}