You can quite easily sort arrays on multiple attributes using a simple Array.sort(). Consider this array - 1 2 3 4 5 6 const students = [ { name: "Rama", grade: 10, class: 5 }, { name: "Kris", grade: 7, class: 1 }, { name: "Jan", grade: 8, class: 5 }, { name: "Kris", grade: 5, class: 7 } ]; Sorting based on grade is easy.

You can use the ... operator to perform black magic in Javascript. Consider the below example - 1 2 3 4 5 6 const arrNums = [1, 2, 3]; const arrMoreNums = [4, 5, 6]; const allNums = [...arrNums, ...arrMoreNums]; console.log("allNums: ", allNums); // [ 1, 2, 3, 4, 5, 6 ] This is much much more efficient than writing code to go through two loops and merging them.

How can you use methods of one object type against another object type? How can you use the feature to your advantage? In another post, we had discussed how Javascript can use call to invoke methods of a function in a different context. We can use this feature to our advantage.

Check if a given object is empty without considering any custom props defined by prototype. Consider this sample object - 1 const earth = {}; Use Object.entries() or equivalent Object.entries gives us a short way to access entries in an array form. We could just check whether entries are empty to decide whether the parent object is empty.

A function can have its own methods - strange but true. Why? Because everything in Javascript is an object and object can have methods. Consider - 1 2 3 4 5 6 function getSum(x, y) { return x + y; } console.log(getSum(1, 2)); //3 console.log(getSum.call(this, 1, 2)); //3 The first call to getSum is as expected.

Chainable interfaces make your code readable and, arguably, your life more enjoyable. Chainable interfaces are those series of methods that you see chained to an object. You can use them for objects where “relevant”. Commonly used functions It is common to see methods chained to one another. The chaining works from left to right, with results from the left-side of the function passed to the right in sequence.

Do not set properties to null or empty, always use delete. Consider - 1 2 3 const earth = { name: "earth", position: 3, aweIndex: 42 }; console.log(earth); // { name: 'earth', position: 3, aweIndex: 42 } If you set any property to null - 1 2 3 earth["aweIndex"] = undefined; console.

Check if a given object has a specified property. You can either use non-enumerable props or hasOwnProperty. Consider the below code - 1 2 3 4 Object.prototype.awesomeness = 42; const earth = {}; console.log(earth["awesomeness"]); // 42 We have defined a prototype that gets attached to any object. Therefore the prop defined by prototype is attached to the object as well.

Use Array.some() and Array.every() to check whether an array has elements that satisfy the given criteria. Consider the below array - 1 const nums = [3, 5, 6, 1, 2]; You can check whether the elements satisfy a specified criteria with below code - 1 2 console.

Often my server DB functions return the data in JSON format with all fields and values thrown in. 1 const alphaNum = { a: 1, b: 2, c: 3, d: 4, e: 5 }; When we use charts (or even tables), this needs to be converted to an array of arrays.

Initializing objects can be a pain. You may end up with multiple checks if you are trying to set a specific prop in the object path to a pre-defined value. For e.g. set color of a Kawasaki bike to ‘blue’. To do this we have to traverse through the object path from the root through color.

Use array filters to remove duplicates in an array. We have seen how we could use sets or an intermediate object in a loop to eliminate duplicates within array.There always is a better way of doing things. Why not use filter to make the code more readable and not use set at the same time :) ?

Are you doing array search using the old school for-loops? Time to change, kid. Consider this array - 1 2 3 4 5 const fruits = [ { name: "apple", color: "red" }, { name: "orange", color: "orange" }, { name: "pear", color: "green" } ]; To search for a specific value -