Easily convert objects to arrays and iterate to your heart’s content. There are multiple ways of converting an object to an array (which, also is an object but a different one at that.) Method 1: A simple Object.values() method The first idea that comes to mind is to just use Object.

Here’s a different syntax for our favourite IIFE’s. Immediately invoked function expressions enable us to write functions without using “functions”. Well - just kidding. They are functions but with a different syntax. A typical IIFE looks like this - 1 2 3 4 5 6 7 8 9 10 11 const x = 1, y = 9; var sum = 0; (function() { sum = x + y; console.

Typescript supports public, private and protected modifiers that affect the accessibility of class in different ways. Access modifiers further a core concept of object oriented programming - ‘encapsulation’. The accessibility of variables and members of a class are driven by modifiers and therefore controlled in the programming flow. Let’s start with a simple class example.

Typescript allows use of static variables and methods just like modern Javascript. Static variables and methods are declared with a keyword static. Static variables Static variables exist within the class context, and are not carried forward to the object of the class. Define a static variable like so - 1 2 3 class Human { static chaos: boolean = true; } The variable value is accessible using the class.

Typescript’s type assertion features help us to override type inference and indicate a specific type to a variable. Type assertion may not be the most common of the features you employ, but it is invaluable when you are migrating from Javascript. Or, when you have to interact with Javascript libraries or data from external systems in your Typescript code.

Here’s a shorter, readable way to copy props from one object to another subject to defined conditions. The shortest way to copy object (when you don’t quite care about copying sub objects by reference) - 1 2 3 4 5 const planet = { name: "earth", position: 3 }; const newPlanet = { .

There are situations when you need to initialize object without props. How do you manage that it Typescript? Let’s consider the example below. First, we declare the object and initialize it to an empty object. 1 const planet = {}; Then, we add the props - 1 planet.

A simpler way to do curry functions in Javascript. We have previously seen currying in Javascript. A simple form and application of that concept is demonstrated below - 1 2 3 const addThem = add.curry(2); const addTotal = addThem(1); console.log("addTotal: ", addTotal); // 3 Or, we could avoid a external function or library and curry using bindings .

Typescript provides a way to indicate props in an object / type, or an entire type, as read only. Props in an object Consider this example - 1 2 3 4 class Fruit { readonly name = "apple"; color = "red"; } In the code block we have specified the prop name as read-only.

Typeguards enable us to process function arguments based on their types. Consider this example - 1 2 3 4 5 function join(a: string): string { return a; } console.log(join("hello")); // hello What if we want to use join for strings or numbers? We can do a union type like so -

Typescript provides a convenient way to accept different types of arguments for a function, or to combine multiple types into one super type. Consider this example - 1 2 3 4 5 function printThis(a: string) { return typeof a; } console.log(printThis("hello")); // string This function is fine if we want to return the input string for some strange reason.

Overload functions to change signatures and provide optional arguments in Typescript. We have previously seen an option to provide optional arguments to a function in Typescript. But, there is more to that to function overloads. Building on our previous example - 1 2 3 4 5 6 7 8 function getSum(i: number, j?

Let us discuss everyone’s favourite topic since Typescript was invented - ‘duck typing’. Duck typing is type safety checks for complex types. It gets its name following the adage - If it walks like a duck and quacks like a duck, it must be a duck. Typescript modifies it slightly to -