🚀 JavaScript Tips — Part 2

1️⃣ Use strict mode when appropriate

Strict mode helps catch certain common mistakes and prevents some unsafe behaviors.

"use strict";

2️⃣ Use optional chaining for uncertain data

When working with API responses or nested objects, optional chaining can prevent errors when a property doesn't exist.

const user = {};
console.log(user.address?.city);

3️⃣ Understand || vs ??

They behave differently when dealing with falsy values.

const count = 0;
console.log(count || 10); // 10

console.log(count ?? 10); // 0

Use ?? when 0, false, or an empty string are valid values.

4️⃣ Don't overuse ternary operators

Ternary operators are great for simple conditions.

const age = 20;
const status = age >= 18 ? "Adult" : "Minor";

For complicated logic, a normal if...else is usually easier to read.

5️⃣ Use destructuring when it improves readability

Destructuring can make working with objects and arrays cleaner.

const user = {
    name: "Alex",
    age: 25
};
const { name, age } = user;

6️⃣ Understand spread vs rest

The same ... syntax has two different purposes.

Spread → expands values

const numbers = [1, 2, 3];
const copy = [...numbers];

Rest → collects values

function sum(...numbers) {
    return numbers.length;
}

7️⃣ Don't rely on implicit type coercion

JavaScript can automatically convert types, sometimes producing surprising results.

console.log("10" + 5); // "105"
console.log("10" - 5); // 5

Be explicit when conversion matters.

8️⃣ Handle asynchronous errors properly

Don't assume every API request or asynchronous operation will succeed.

async function getData() {
    try {
        const response = await fetch("/api/data");
        const data = await response.json();
        return data;
    } catch (error) {
        console.error("Request failed:", error);
    }
}

9️⃣ Don't block the main thread

Heavy calculations or large amounts of synchronous work can make a web application unresponsive.

For expensive tasks, consider:

• Breaking work into smaller tasks

• Web Workers

• Efficient algorithms

• Avoiding unnecessary rendering

🔟 Use debounce and throttle appropriately

These techniques are useful when an event fires repeatedly.

Debounce → Run after activity stops.

Throttle → Limit execution to a controlled frequency.

Common use cases: Search inputs, Scrolling, Resizing, Mouse movement

1️⃣1️⃣ Use const objects carefully

const prevents reassignment of the variable, but it doesn't make the object immutable.

const user = {
    name: "Alex"
};
user.name = "Sam"; // Allowed

Understanding this distinction is important.

1️⃣2️⃣ Don't blindly use JSON.parse() and JSON.stringify()

They are useful for JSON data, but they aren't universal deep-copy solutions. They can lose or alter certain JavaScript values and don't preserve all object types.

For structured cloning, consider structuredClone() when appropriate.

1️⃣3️⃣ Use === consistently

Strict equality makes your comparisons easier to reason about.

if (status === "active") {
    console.log("User is active");
}