30 JavaScript Tricky Hacks

mainulspace

Mainul Hasan

Posted on March 3, 2024

30 JavaScript Tricky Hacks

Welcome to our curated collection of JavaScript tricks, which will help you optimize your code, make it more readable, and save you time.

Let’s dive into the depths of JavaScript functionalities and hacks that go beyond the conventional and discover the full potential of this powerful programming language.

1. Using !! to Convert to Boolean

Quickly convert any value to a boolean by using double negation.




        let truthyValue = !!1; // true
        let falsyValue = !!0; // false



Enter fullscreen mode Exit fullscreen mode

2. Default Function Parameters

Set default values for function parameters to avoid undefined errors.




        function greet(name = "Guest") {
            return `Hello, ${name}!`;
        }



Enter fullscreen mode Exit fullscreen mode

3. The Ternary Operator for Short If-Else

A shorthand for the if-else statement.




        let price = 100;
        let message = price > 50 ? "Expensive" : "Cheap";



Enter fullscreen mode Exit fullscreen mode

4. Template Literals for Dynamic Strings

Use template literals for embedding expressions in strings.




        let item = "coffee";
        let price = 15;
        console.log(`One ${item} costs $${price}.`);



Enter fullscreen mode Exit fullscreen mode

5. Destructuring Assignment

Easily extract properties from objects or arrays.




        let [x, y] = [1, 2];
        let {name, age} = {name: "Alice", age: 30};



Enter fullscreen mode Exit fullscreen mode

6. The Spread Operator for Array and Object Cloning

Clone arrays or objects without referencing the original.




        let originalArray = [1, 2, 3];
        let clonedArray = [...originalArray];



Enter fullscreen mode Exit fullscreen mode

7. Short-circuit Evaluation

Use logical operators for conditional execution.




        let isValid = true;
        isValid && console.log("Valid!");



Enter fullscreen mode Exit fullscreen mode

8. Optional Chaining (?.)

Safely access nested object properties without an error if a reference is nullish.




        let user = {name: "John", address: {city: "New York"}};
        console.log(user?.address?.city); // "New York"



Enter fullscreen mode Exit fullscreen mode

9. Nullish Coalescing Operator (??)

Use ?? to provide a default value for null or undefined.




        let username = null;
        console.log(username ?? "Guest"); // "Guest"



Enter fullscreen mode Exit fullscreen mode

Interactive banner for monday.com showcasing hands organizing workflow tasks on a digital interface with a call-to-action button ‘Show me how’.

10. Using map, filter, and reduce for Array Manipulation

Elegant ways to handle arrays without traditional loops.




        // Map
        let numbers = [1, 2, 3, 4];
        let doubled = numbers.map(x => x * 2);

        // Filter
        const evens = numbers.filter(x => x % 2 === 0);

        // Reduce
        const sum = numbers.reduce((accumulator, currentValue) => accumulator + currentValue, 0);



Enter fullscreen mode Exit fullscreen mode

11. Tagged Template Literals

Function calls using template literals for custom string processing.




        function highlight(strings, ...values) {
            return strings.reduce((prev, current, i) => `${prev}${current}${values[i] || ''}`, '');
        }
        let price = 10;
        console.log(highlight`The price is ${price} dollars.`);



Enter fullscreen mode Exit fullscreen mode

12. Using Object.entries() and Object.fromEntries()

Convert objects to arrays and back for easier manipulation.




        let person = {name: "Alice", age: 25};
        let entries = Object.entries(person);
        let newPerson = Object.fromEntries(entries);



Enter fullscreen mode Exit fullscreen mode

13. The Set Object for Unique Elements

Use Set to store unique values of any type.




        let numbers = [1, 1, 2, 3, 4, 4];
        let uniqueNumbers = [...new Set(numbers)];



Enter fullscreen mode Exit fullscreen mode

14. Dynamic Property Names in Objects

Use square brackets in object literal notation to create dynamic property names.




        let dynamicKey = 'name';
        let person = {[dynamicKey]: "Alice"};



Enter fullscreen mode Exit fullscreen mode

15. Function Currying Using bind()

Create a new function that, when called, has its this keyword set to the provided value.




        function multiply(a, b) {
            return a * b;
        }
        let double = multiply.bind(null, 2);
        console.log(double(5)); // 10



Enter fullscreen mode Exit fullscreen mode

16. Using Array.from() to Create Arrays from Array-like Objects

Convert array-like or iterable objects into true arrays.




        let nodeList = document.querySelectorAll('div');
        let nodeArray = Array.from(nodeList);



Enter fullscreen mode Exit fullscreen mode

17. The for…of Loop for Iterable Objects

Iterate over iterable objects (including arrays, maps, sets, etc.) directly.




        for (let value of ['a', 'b', 'c']) {
            console.log(value);
        }



Enter fullscreen mode Exit fullscreen mode

18. Using Promise.all() for Concurrent Promises

Run multiple promises concurrently and wait for all to settle.




        let promises = [fetch(url1), fetch(url2)];
        Promise.all(promises)
        .then(responses => console.log('All done'));



Enter fullscreen mode Exit fullscreen mode

19. The Rest Parameter for Function Arguments

Capture any number of arguments into an array.




        function sum(...nums) {
            return nums.reduce((acc, current) => acc + current, 0);
        }



Enter fullscreen mode Exit fullscreen mode

Coursera Plus subscription offerings including AWS Fundamentals, Google IT Support Professional Certificate, and Cyber Security for Business Specialization.

20. Memoization for Performance Optimization

Store function results to avoid redundant processing.




        const memoize = (fn) => {
            const cache = {};
            return (...args) => {
                let n = args[0];  // assuming single argument for simplicity
                if (n in cache) {
                    console.log('Fetching from cache');
                    return cache[n];
                }
                else {
                    console.log('Calculating result');
                    let result = fn(n);
                    cache[n] = result;
                    return result;
                }
            };
        };



Enter fullscreen mode Exit fullscreen mode

21. Using ^ for Swapping Values

Swap the values of two variables without a temporary variable using the XOR bitwise operator.




        let a = 1, b = 2;
        a ^= b; b ^= a; a ^= b; // a = 2, b = 1



Enter fullscreen mode Exit fullscreen mode

22. Flattening Arrays with flat()

Easily flatten nested arrays using the flat() method, with the depth of flattening as an optional argument.




        let nestedArray = [1, [2, [3, [4]]]];
        let flatArray = nestedArray.flat(Infinity);



Enter fullscreen mode Exit fullscreen mode

23. Converting to Numbers with Unary Plus

Quickly convert strings or other values to numbers using the unary plus operator.




        let str = "123";
        let num = +str; // 123 as a number



Enter fullscreen mode Exit fullscreen mode

24. Template Strings for HTML Fragments

Use template strings to create HTML fragments, making dynamic HTML generation cleaner.




        let items = ['apple', 'orange', 'banana'];
        let html = `<ul>${items.map(item => `<li>${item}</li>`).join('')}</ul>`;



Enter fullscreen mode Exit fullscreen mode

25. Using Object.assign() for Merging Objects

Merge multiple source objects into a target object, effectively combining their properties.




        let obj1 = { a: 1 }, obj2 = { b: 2 };
        let merged = Object.assign({}, obj1, obj2);



Enter fullscreen mode Exit fullscreen mode

Ergonomic vertical mouse designed to reduce wrist strain

Optimize your programming setup with an ergonomic mouse, tailored for comfort and long coding sessions.

26. Short-circuiting for Default Values

Utilize logical operators to assign default values when dealing with potentially undefined or null variables.




        let options = userOptions || defaultOptions;



Enter fullscreen mode Exit fullscreen mode

27. Dynamically Accessing Object Properties with Bracket Notation

Access properties of an object dynamically using bracket notation, useful when the property name is stored in a variable.




        let property = "name";
        let value = person[property]; // Equivalent to person.name



Enter fullscreen mode Exit fullscreen mode

28. Using Array.includes() for Presence Check

Check if an array includes a certain value with includes(), a clearer alternative to indexOf.




        if (myArray.includes("value")) {
            // Do something
        }



Enter fullscreen mode Exit fullscreen mode

29. The Power of Function.prototype.bind()

Bind a function to a context (this value) and partially apply arguments, creating more reusable and modular code.




        const greet = function(greeting, punctuation) {
            return `${greeting}, ${this.name}${punctuation}`;
        };
        const greetJohn = greet.bind({name: 'John'}, 'Hello');
        console.log(greetJohn('!')); // "Hello, John!"



Enter fullscreen mode Exit fullscreen mode

30. Preventing Object Modification

Prevent modifications to an object using Object.freeze(), making it immutable. For deeper immutability, consider libraries that enforce immutability more thoroughly.




        let obj = { name: "Immutable" };
        Object.freeze(obj);
        obj.name = "Mutable"; // Fails silently in non-strict mode



Enter fullscreen mode Exit fullscreen mode

I hope these JavaScript tricks provide you with new perspectives on how to approach JavaScript programming.

From leveraging the concise power of template literals to mastering the efficiency of map, filter, and reduce, these JavaScript hacks will enrich your development workflow and inspire your next project.

Let these JavaScript tricks not only refine your current projects but also spark inspiration for future innovations in your coding journey.

Support Our Tech Insights

Buy Me A Coffee

Donate via PayPal button

Note: Some links on this page might be affiliate links. If you make a purchase through these links, I may earn a small commission at no extra cost to you. Thanks for your support!

💖 💪 🙅 🚩
mainulspace
Mainul Hasan

Posted on March 3, 2024

Join Our Newsletter. No Spam, Only the good stuff.

Sign up to receive the latest update from our blog.

Related

30 JavaScript Tricky Hacks
javascript 30 JavaScript Tricky Hacks

March 3, 2024