Coercions are useful and almost intuitive, but beware of pitfalls. Consider below block of code - 1 const x = 42; Numbers greater than 0 and not undefined are generally considered truthy. So, following is understandable - 1 2 if (x) console.log("found the answer"); // found the answer But, you will be surprised if you do this -

I like Array.forEach() and use it whenever I need to iterate through elements. However one needs to be aware of its quirk. 1 2 3 const arr = new Array(5); arr[0] = 0; arr[4] = 4; A typical for outputs all elements including those not initialized yet (hold your breath for a moment on the initialized thing).

Both indexOf() and find() are used for finding a pattern within an array. How are they different? indexOf requires the exact string to search within array. 1 2 3 4 const nums = [1, 3, 5, 7, 9]; console.log(nums.indexOf(3)); // 1 indexOf behaves very much like its string counterpart which helps to search a substring within a string.

How do you set a variable as the prop of an object? Consider the below code - 1 const earth = { name: "earth" }; If we have a dynamic prop for earth, we can do - 1 2 3 4 5 6 let lifeExists = "life"; const earth = { name: "earth" }; earth[lifeExists] = true; console.

Creating a null object is simple, but not in the way you may think. Consider the below code - 1 const earth = {}; earth is empty but not null. See - 1 2 3 4 5 6 7 8 9 10 11 console.log(Object.toString(earth)); // function Object() { [native code] } console.

Swapping variables is simple enough, but can it be any simpler? Consider the below code - 1 2 let x = 1; let y = 3; To swap values - 1 2 3 4 5 6 let z = x; x = y; y = z; console.

Type conversion is a big deal, but not anymore? Just use maps against a given array and them conversion shortcuts to simplify type conversion in Javascript. Consider the below array - 1 const nums = [1, 3, 5, 7, 9]; We can convert the type to string using a map.

Destructuring is useful but what if you have conflicts with the variable names provided by the object being imported? Consider the following example where we destructure arguments of a function. 1 2 3 4 5 6 7 8 const getSum = nums => { let { x, y } = { .

Specifying one or more arguments as required is one of the common patterns in Javascript. We will see one of the ways in which we can (arguably) make it more simple. Consider the function below - 1 2 3 4 5 6 function getSum(x, y) { return x + y; } console.

Conditional statements and objects - are we talking about the same thing here? Do they have anything in common? Not quite similar, but you could simplify your conditional statements using objects. Consider the below tax rate calculation logic - 1 2 3 4 5 6 7 8 9 10 11 12 13 14 const incomeLevel = "high"; let taxRate; if (incomeLevel == "very low") { taxRate = income * 0.

When should use maps? What are maps anyway? Using an object is cool. We do it all the time - 1 const earth = { name: "earth", position: 3 }; What if we do not have all props at once, but rather incrementally assign props. 1 2 3 4 5 6 7 8 9 10 const earth = { name: "earth", position: 3 }; for (ele in earth) { console.

Javascript does not have goto - thankfully. But it has continue and break that more or less perform the same function. If for any reason you want to jump out of a loop, here’s how you can do that - 1 2 3 4 for (let i = 0; i < 10; i++) { console.

Use workers when doing lot of work that can be spawned off in another “thread”. How do you open parallel work threads today? Possibly using async functions? Async functions do not block the main thread but allow processing to take place in parallel. Well, almost in parallel - see how event loops work.