TypeScript Interview Questions and Answers
The word of development is rapidly growing, so as the programming languages associated with it. TypeScript is one of these increasingly popular programming languages. We will discuss several advanced TypeScript interview questions while further continuing here for your practice. TypeScript is an object-oriented, open-source, strongly typed and compiled programming language. It’s a typed superset of JavaScript (compiled to JavaScript) and can be used for JavaScript application development supported to server-side and client-side execution.
Simplifying it, TypeScript is an advanced version of JavaScript with additional features to help both programming language and new tool requirements for developers. With the conclusion of basic TypeScript knowledge, now let’s continue with our expert-selected, crucial TypeScript interview questions with the suggested answer that may help you crack your next big interview.
Benefits of TypeScript
- With TypeScript, the production of pure object-oriented code is possible even with limited knowledge as this is completely object-oriented programming.
- It can be used for both server-side and client-side development alike.
- TypeScript comes with types that make code easier to read and void major errors.
- As it’s a package, TypeScript can be installed on projects via npm. This will make new features available and compile to all modern browsers.
- TypeScript offers an API for DOM manipulation.
- It also has the concept of the namespace by Module defining.
- With IDE support here, developers will save a ton of valuable time here.
Most Frequently Asked TypeScript Interview Questions
TypeScript is strongly typed to syntactical benefits to this language while still allowing users to write normal JavaScript. It also ensures the production of predictable results with fewer errors and more secure.
For compiling a Typescript file, follow these steps carefully:
- Install the Typescript compiler, tsc.
- Add a tsconfig.json file
- Transpile Typescript into Javascript
- Compile with the --sourcemap or set the sourceMap property in the tsconfig.json file as true for map support.
In Typescript, the Asynchronous Module Definition (AMD) is used to specify a process for defining modules in a manner such that modules and their dependencies can be loaded asynchronously. This is greatly helpful in a browser environment where performance, usability, debugging, and access to cross-domain problems occur due to the synchronous loading of modules.
The two significant benefits that Arrow function in TypeScript offers:
- They are less verbose compared to traditional functions.
- This function takes the “this” from its surroundings.
Inheritance can be implemented in Typescript through the following:
- GO to Visual Studio, then, File -> New-> Project
- Select HTML application with Typescript as Visual C# template and name it as Inheritance.
- Now, write the code below in which a class “Student” is used to display the position of students in a class.
class Students {
constructor(public name) {}
Position(Div) {
alert(this.name + " " + "Position in the School is:" + Div);
}
}
class Student1 extends Students {
constructor(name) {
super(name);
}
Position() {
alert("Student1");
super.Position(2);
}
}
class Student2 extends Students {
constructor(name) {
super(name);
}
Position() {
alert("Student2");
super.Position(4);
}
}
var one = new Student1("Rohan")
var two: Students = new Student2("Mohan")
one.Position()
two.Position(34) - Code this command in the default htm.file
<html>
<head>
<title>Simple Inheritance In TypeScript</title>
</head>
<body >
<h1>Simple Inheritance In TypeScript</h1>
<script src="app.js"></script>
</body>
</html> - The output of this application should be like this:
- Click OK and the position of any student will be displayed
| S.no | TypeScript | ES6 |
|---|---|---|
| 1. | Extremely comfortable to eradicate the development error. | ES6 is more comfortable in development deployment. |
| 2. | It’s an open source programming language. | It’s a scripting language. |
| 3. | It supports all primitive data types. | ES6 doesn’t support primitive data types. |
| 4. | TypeScript has 3 scopes: Global, Class, and Local. | It has only two scopes: Global and Local. |
In Typescript, an object is used to store a set of key-value pairs. Following is a syntax for creating an object in Typescript:
var object_name = {
key1: “value1”,
key2: “value”,
key3: function() {
},
key4:[“content1”, “content2”]
};
Here is a list of benefits developers can enjoy with the use of TypeScript.
- TypeScript supports optional static typing.
- Incredible code scalability due to interface oriented development.
- Compliance with ES-next.
- Enhances code readability and quality with Types.
- Use of advance compilers to check errors.
- It includes dependency injection, which offers great testing and controller based APIs.
- Extremely predictable and maintainable code-base.
- Implementation of SOLID design patterns into a language is easy here.
- Clean code generation due to static typing.
- Refactoring is easy and fasts with TypeScript tools.
| S.no | TypeScript | JavaScript |
|---|---|---|
| 1. | Typescript is an object-oriented language. | JavaScript is a scripting language. |
| 2. | Static typing feature is available here. | Doesn’t support static typing. |
| 3. | TypeScript supports modules. | JavaScript doesn’t support modules. |
| 4. | It has an interface. | Doesn’t have any interface. |
| 5. | The optional parameter function is supported here. | JavaScript doesn’t support optional parameter function. |
In TypeScript, decorators are used to offering a way to add both meta-programming syntax and annotations for members and declarations.