TypeScript Compiler Installation and Setup - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the command to install the TypeScript compiler globally using npm?

The command is npm install -g typescript. This installs the TypeScript compiler so you can use the tsc command anywhere on your computer.

beginner

What does the tsc command do?

The tsc command runs the TypeScript compiler. It converts TypeScript files (.ts) into JavaScript files (.js) that browsers can understand.

beginner

Why do we need to install Node.js before installing TypeScript?

Node.js provides the npm tool, which is used to install TypeScript and other packages. Without Node.js, you cannot use npm to install the TypeScript compiler.

intermediate

What is the purpose of the tsconfig.json file in a TypeScript project?

The tsconfig.json file tells the TypeScript compiler how to compile your project. It sets options like which files to include, the JavaScript version to output, and other settings.

beginner

How can you check if TypeScript is installed correctly on your system?

Run the command tsc --version in your terminal or command prompt. If it shows a version number, TypeScript is installed correctly.

Which command installs TypeScript globally on your computer?

A npm install typescript

B node install typescript

C tsc install

D npm install -g typescript

The correct command is npm install -g typescript to install TypeScript globally.

What file extension does TypeScript use for its source files?

A .ts

B .js

C .tsx

D .json

TypeScript source files use the .ts extension.

What is the main purpose of the TypeScript compiler?

A To run JavaScript code

B To convert JavaScript to TypeScript

C To convert TypeScript to JavaScript

D To install Node.js

The TypeScript compiler converts TypeScript code into JavaScript code.

Before installing TypeScript, which software must be installed first?

A Python

B Node.js

C Java

D Git

Node.js must be installed first because it provides npm, which installs TypeScript.

What command checks the installed TypeScript version?

A tsc --version

B npm version typescript

C node --version

D tsc check

Use tsc --version to check the installed TypeScript version.

Explain the steps to install and verify the TypeScript compiler on your computer.

Think about what tools you need and how to check if TypeScript is ready to use.

Describe the role of the tsconfig.json file in a TypeScript project setup.

It's like a settings file for the TypeScript compiler.

Practice

1. What command do you use to install the TypeScript compiler globally on your system?

easy

A. npm install typescript

B. tsc install

C. npm install -g typescript

D. install typescript -g

Solution

1. Step 1: Understand global installation

   To use TypeScript compiler anywhere, it must be installed globally using npm with the -g flag.

2. Step 2: Identify correct npm command

   The correct command is npm install -g typescript which installs TypeScript globally.

3. Final Answer:

   npm install -g typescript -> Option C

4. Quick Check:

   Global install uses npm install -g [OK]

Hint: Use npm install -g to install global packages [OK]

Common Mistakes:

• Forgetting the -g flag for global install
• Using 'tsc install' which is invalid
• Installing locally without -g

2. Which of the following commands correctly compiles a TypeScript file named app.ts into JavaScript?

easy

A. tsc app.js

B. tsc app.ts

C. npm run app.ts

D. compile app.ts

Solution

1. Step 1: Identify the TypeScript compiler command

   The TypeScript compiler command is tsc followed by the TypeScript file name.

2. Step 2: Match the correct file extension

   We must compile the .ts file, so the command is tsc app.ts.

3. Final Answer:

   tsc app.ts -> Option B

4. Quick Check:

   Compile with tsc filename.ts [OK]

Hint: Use tsc followed by .ts filename to compile [OK]

Common Mistakes:

• Trying to compile .js files with tsc
• Using npm run instead of tsc
• Typing wrong command like 'compile'

3. After installing TypeScript globally, what will be the output of the command tsc --version if the installed version is 5.1.3?

medium

A. TypeScript 5.1.3

B. tsc version: 5.1.3

C. 5.1.3

D. Version 5.1.3

Solution

1. Step 1: Understand tsc --version output format

   The tsc --version command outputs 'TypeScript 5.1.3'.

2. Step 2: Match output to options

   Only 'TypeScript 5.1.3' matches the exact output format.

3. Final Answer:

   TypeScript 5.1.3 -> Option A

4. Quick Check:

   tsc --version outputs 'TypeScript X.Y.Z' [OK]

Hint: tsc --version shows 'TypeScript X.Y.Z' [OK]

Common Mistakes:

• Expecting only the version number without 'TypeScript ' prefix
• Confusing output with npm version output
• Adding extra text like 'Version'

4. You run tsc app.ts but get an error: tsc: command not found. What is the most likely cause?

medium

A. Node.js is not installed

B. app.ts file has syntax errors

C. You need to run npm start instead

D. TypeScript is not installed globally or PATH is not set

Solution

1. Step 1: Analyze the error message

   The error 'tsc: command not found' means the system cannot find the TypeScript compiler command.

2. Step 2: Identify cause of missing command

   This usually happens if TypeScript is not installed globally or the system PATH does not include the location of tsc.

3. Final Answer:

   TypeScript is not installed globally or PATH is not set -> Option D

4. Quick Check:

   Command not found means missing install or PATH [OK]

Hint: Check if tsc is installed globally and in PATH [OK]

Common Mistakes:

• Assuming syntax errors cause command not found
• Trying npm start which is unrelated
• Thinking Node.js absence causes this error

5. You want to compile multiple TypeScript files in a project folder without typing each filename. Which setup helps you compile all files at once?

hard

A. Create a tsconfig.json file and run tsc without arguments

B. Run tsc *.ts in the terminal

C. Install TypeScript locally and run npm compile

D. Use tsc --all command

Solution

1. Step 1: Understand how to compile multiple files

   TypeScript uses a tsconfig.json file to configure project compilation settings for multiple files.

2. Step 2: Use tsc with tsconfig.json

   Running tsc without arguments reads tsconfig.json and compiles all files specified there.

3. Final Answer:

   Create a tsconfig.json file and run tsc without arguments -> Option A

4. Quick Check:

   tsconfig.json enables project-wide compilation [OK]

Hint: Use tsconfig.json and run tsc alone to compile all [OK]

Common Mistakes:

• Trying to use wildcard *.ts which may not work in all shells
• Assuming npm compile is a default command
• Using non-existent tsc --all option