9 Hidden JavaScript Features You Probably Don’t Know Exist 🤯

JavaScript has many hidden tricks that most developers don’t know yet. These 9 hidden JavaScript features can make coding easier and save your time a lot. Let’s explore all 9 amazing JavaScript secrets with us! 🚀 Welcome to our blog and enhance your JS coding skills with our tutorials!

🧐 1. The ?? Nullish Coalescing Operator

?? helps when checking for null or undefined. It is better than || because it does not treat "" or 0 as false. Unlike ||, it only considers null and undefined as falsy values, making it safer for real data.

JavaScript Double Question Mark vs Or: A Comprehensive Guide

let username = "";
console.log(username || "Guest");  // Outputs: Guest ❌
console.log(username ?? "Guest");  // Outputs: "" ✅

Operator	Works On	Problem	Solution
||	Any falsy value	Treats "" and 0 as false	Not ideal for all cases
??	Only null or undefined	Safer for real values	✅ Better choice

🔥 2. The ?. Optional Chaining Operator

No more TypeErrors when dealing with nested objects! 🚀

let user = { profile: { name: "Alice" } };
console.log(user.profile?.name);   // Outputs: Alice ✅
console.log(user.settings?.theme); // Outputs: undefined ✅

🎭 3. Object.hasOwn() – A Safer hasOwnProperty()

Object.hasOwn() is better and safer for checking if an object really owns a property.

const obj = { key: "value" };
console.log(Object.hasOwn(obj, "key")); // true ✅
console.log(Object.hasOwn(obj, "toString")); // false ✅

⚡ 4. replaceAll() for String Replacements

Use replaceAll() to replace multiple matches easily.

let text = "banana apple banana orange";
console.log(text.replaceAll("banana", "grape"));
// Outputs: "grape apple grape orange"

🏆 5. The at() Method for Arrays and Strings

at() makes it easy to get the last item in an array. 🔥

const fruits = ["apple", "banana", "cherry"];
console.log(fruits.at(-1)); // Outputs: "cherry" ✅

🎩 6. Numeric Separators for Readable Numbers

Big numbers can be hard to read. _ makes them clearer. 🤯

const billion = 1_000_000_000;
console.log(billion); // Outputs: 1000000000 ✅

🛠️ 7. structuredClone()Deep Copy Made Easy

Forget manual deep cloning—JavaScript now has a built-in way! 🎉

const obj = { name: "Alice", skills: ["JS", "React"] };
const clone = structuredClone(obj);
clone.skills.push("Node.js");
console.log(obj.skills); // Outputs: ["JS", "React"] ✅

🧙 8. groupBy() for Arrays (Coming Soon!)

Grouping array items will soon be super easy. 🤩

const items = ["apple", "banana", "grape", "blueberry"];
console.log(groupBy(items, (item) => item.length));
// Outputs: { 5: ["apple", "grape"], 6: ["banana"], 9: ["blueberry"] }

💡 Bonus: Math.trunc() for Quick Integer Extraction

Math.trunc() removes decimals without rounding up or down! 🔥

console.log(Math.trunc(4.9)); // Outputs: 4 ✅
console.log(Math.trunc(-4.9)); // Outputs: -4 ✅

Method	Input	Output	Remarks
Math.trunc()	4.9	4	Removes decimals without rounding
Math.trunc()	-4.9	-4	Same behavior for negative numbers
Math.floor()	4.9	4	Rounds down to the nearest integer
Math.ceil()	4.1	5	Rounds up to the nearest integer
Math.round()	4.5	5	Rounds to the nearest integer

❓ Frequently Asked Questions (FAQ)

Conclusion

JavaScript has many hidden tricks that can save time and make coding fun. Try them out and let us know which one is your favorite! 😃✨

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