一文总结5个JavaScript代码优化技巧

const target = {};
const handler = {
    get: (target, prop) => {
        console.log(`获取属性：${prop}`);
        return target[prop];
    },
    set: (target, prop, value) => {
        console.log(`属性 ${prop} 更新为 ${value}`);
        target[prop] = value;
    },
};
const proxy = new Proxy(target, handler);

proxy.name = "DevPoint";
console.log(proxy.name);

const x = 5;
const result = x > 0 ? "positive" : "negative";
console.log(result); // positive

const age = 30;
const result =
    age < 18 ? "未成年人" : age >= 18 && age < 60 ? "成年人" : "老年人";
console.log(result); // 成年人

(function () {
    let key = "这是一个安全密钥";
})();
console.log(key); // ReferenceError: key is not defined

(function initGame() {
    // 无法在 IIFE 外部访问的私有变量
    var lives;
    var player;

    init();

    // 在 IIFE 之外无法访问的私有函数
    function init() {
        lives = 5;
        player = "devpoint";
    }
})();

(function ($, global, document) {
    // 对 jQuery 使用 $，对 window 使用 global
})(jQuery, window, document);