TypeScript Compiler Installation and Setup - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output after compiling and running this TypeScript code?

Consider this TypeScript code snippet. After compiling it with the TypeScript compiler and running the resulting JavaScript, what will be printed to the console?

Typescript

const greet = (name: string): string => {
  return `Hello, ${name}!`;
};

console.log(greet("Alice"));

A Hello, Alice!

B greet("Alice")

C Error: name is not defined

D undefined

💡 Hint

Think about what the function returns and what console.log prints.

The function greet returns the string 'Hello, Alice!'. When compiled and run, console.log prints this string to the console.

🧠 Conceptual

intermediate

Which command installs the TypeScript compiler globally?

You want to install the TypeScript compiler so you can use the 'tsc' command anywhere on your computer. Which command should you run?

A npm install typescript@latest

B npm install -g typescript

C npm install --save-dev typescript

D npm install typescript

💡 Hint

Global installation allows using the command in any folder.

The '-g' flag installs the package globally, making the 'tsc' command available everywhere.

🔧 Debug

advanced

What error occurs when compiling this TypeScript code?

Look at this TypeScript code. When you run 'tsc' to compile it, what error will the compiler show?

Typescript

let count: number = "five";
console.log(count);

A ReferenceError: count is not defined

B SyntaxError: Unexpected string

C Type 'string' is not assignable to type 'number'.

D No error, compiles successfully

💡 Hint

Check the type assigned to 'count' and the declared type.

The variable 'count' is declared as a number but assigned a string, causing a type error.

📝 Syntax

advanced

Which command compiles all TypeScript files in the current folder using a config file?

You have a 'tsconfig.json' file in your project folder. Which command compiles all TypeScript files according to this config?

A tsc -p tsconfig.json

B tsc --project tsconfig.json

C tsc --config tsconfig.json

D tsc --all

💡 Hint

The '-p' flag specifies the project config file.

The '-p' or '--project' flag tells 'tsc' to use the given config file to compile the project.

🚀 Application

expert

How many JavaScript files are generated after compiling this project?

You have a project with these files: 'app.ts', 'utils.ts', and 'data.ts'. Your 'tsconfig.json' has "outDir": "dist" and "include": ["*.ts"]. After running 'tsc -p tsconfig.json', how many JavaScript files will appear in the 'dist' folder?

A 3

B 0

C 1

D Depends on the content of the files

💡 Hint

Each TypeScript file compiles to one JavaScript file unless excluded.

All three '.ts' files are included and compiled, producing three '.js' files in the output folder.