TypeScript Test

Question 2: TypeScript is a typed superset of __________.

• C#
• Java
• JavaScript
• ReactJS

Question 3: TypeScript file compiled into ________.

• JavaScript
• VBScript
• TypeScript
• None of the above

Question 4: TypeScript can be used to write server side and client side application.

• True
• false

Question 5: _______ command is used to generate a JavaScript file from a TypeScript file.

• npm filename.ts
• tsc fileName.ts
• tsc -js fileName.ts
• All of the above

Question 6: Which of the following statement declares a variable in TypeScript?

• var myVar = 123;
• var myVar:number = 123;
• let myVar:number = 123;
• All of the above

Question 7: Which of the followings are primitive types supported in TypeScript?

• number
• string
• boolean
• All of the above

Question 8: Which of the following is a valid union type variable?

• var emp:[number, string] = [1, "Steve"];
• var emp:(number|string) = 123;
• var emp:string[] = ["Bill"]
• None of the above

Question 9: Which of the following is a valid tuple?

• var employee:[number, string] = [1, "Bill"]
• var employee:(number|string) = 123;
• var employee = [1, "Bill"];
• None of the above

Question 10: Type assertion in TypeScript is achieved using which of the following syntax?

• Using <type> syntax
• Using as syntax
• Both A and B
• None of the above

Question 11: What will be the output of the following code snippet?

let arr = [10, 20, 30, 40];

for(var val of arr) {
    console.log(val);
}

• prints 10, 20, 30, 40
• prints 0, 1, 2, 3
• prints undefined
• Compiler error

Question 12: Which of the following is a valid arrow function?

• let sum = (x: number, y: number) => x + y;
• let sum(): (x: number, y: number):number => x + y;
• let sum = (x: number, y: number) => return x + y;
• let sum:(x: number, y: number) => x + y;

Question 13: The rest parameters in a function is used when _______.

• The types of parameters is not known
• The number of parameters is not known
• The function needs to be executed asynchronously
• The function is called recursively

Question 14: Which of the following statement is TRUE?

• An interface can extend another interface in TypeScript.
• An interface can extend a class in TypeScript.
• TypeScript interface does not generate any JavaScript code.
• All of the above

Question 15: Which of the following are valid data modifiers in TypeScript?

• public
• private
• protected
• All of the above

Question 16: Which of the following keyword is used to declare a module?

• export
• namespace
• type
• declare

Question 17: Which of the followings is declared a namespace?

• namespace test{ }
• ns test { }
• A & B both
• export test(){ }

Question 18: Which of the following command is used to compile a module?

• tsc --module amd mymodule.ts
• tsc -m amd mymodule.ts
• Both, A and B
• None of the above

Question 19: Which configuration file is required to compile the whole TypeScript project?

• tsconfig.js
• tsconfig.json
• web.config
• app.json

Question 20: Which of the following statement is TRUE?

• TypeScript supports generics.
• TypeScript supports readonly and static members.
• TypeScript supports abstract class.
• All of the above.