An article summarizing 5 JavaScript code optimization tips

In this article, we will introduce 5 code optimization tips to help write more efficient and elegant code. These techniques range from using spread operators to simplify code to using async/await to handle asynchronous code.

1. Use the spread operator to destructure objects and arrays

The spread operator is represented by three dots ... and can be used to destructure objects and arrays. For objects, it allows easy creation of a new object using a subset of the properties of another object.

const numbersObj = { a: 1, b: 2, c: 3 };
const newObject = { ...numbersObj, b: 4 };
console.log(newObject); // { a: 1, b: 4, c: 3 }

For arrays, the spread operator makes it easy to extract and manipulate array elements.

const numbersArray = [1, 2, 3, 4, 5];
const newArray = [...numbersArray.slice(0, 2), 6, ...numbersArray.slice(4)];
console.log(newArray); // [ 1, 2, 6, 5 ]

Regarding the destructuring operator, if you are interested, you can refer to:

• 5 common scenarios and examples of JavaScript destructuring assignment
• Let’s talk about object deconstruction in JavaScript

2. Use async/await to simplify asynchronous code

##async/await is a way to simplify JavaScript Methods for handling asynchronous code. It allows writing asynchronous code in a way that looks and behaves like synchronous code.

async function getData() {
    const response = await fetch("https://jsonplaceholder.typicode.com/posts");
    const data = await response.json();
    console.log(data);
}
getData();

3. Use proxy objects for advanced property access

The Proxy object in JavaScript allows interception and custom property access. This is useful for advanced data validation, logging, etc.

The Proxy object is used to create a proxy for an object to implement interception and customization of basic operations (such as property lookup, assignment, enumeration, function calling, etc.).

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);

4. Use the ternary operator to optimize conditional logic

The ternary operator is a way of writing simple

if-else statements in JavaScript Abbreviation. This is a concise and efficient way of expressing conditions and their corresponding consequences.

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

It can also be nested for more complex conditions.

const age = 30;
const result =
    age = 18 && age 5. Use IIFE to protect data privacy<h3 data-id="heading-4"></h3>IIFE is the abbreviation of <p>Immediately Invoked Function Expression<code> (immediately invoked function expression). It is a function that is called when it is defined. A JavaScript function that is executed immediately and creates a private scope for the variable. This is useful for protecting data privacy as it ensures that variables declared in the IIFE cannot be accessed from outside. </code></p>You can use this format to create a package for your application, putting the code logic into a namespace to avoid variable conflicts to keep the code private, and this private package is suitable for <p><script><code> Tags are introduced to the page. You can usually see that WEB statistics code is introduced into the page in this way. <pre class="brush:php;toolbar:false">(function () {
    let key = "这是一个安全密钥";
})();
console.log(key); // ReferenceError: key is not defined</script></p>

What IIFE is really good at is the ability to create scopes. Any variables in IIFE are invisible to the outside world. Reduce the generation of global variables and avoid the chance of variable name conflicts.

Let’s look at an example:

(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";
    }
})();

In this example, two variables are declared, both of which are private, that is, they are only valid for IIFE itself. It is not accessible to anyone outside IIFE. In addition, there is an

init method, which is not accessible from the outside.

If you have read the jQuery source code, you should be familiar with the following code:

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

Summary

By collecting these coding tips, you can improve your ability to write elegant and maintainable code. ability.

Recommended study: "

JavaScript Video Tutorial"

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