path.resolve for absolute paths in Node.js - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of path.resolve with relative and absolute paths?

Consider the following Node.js code using path.resolve. What will be printed?

Node.js

import path from 'path';
console.log(path.resolve('/foo', './bar', 'baz'));

A "/foo/./bar/baz"

B "/foo/bar/baz"

C "/foo/bar/./baz"

D "foo/bar/baz"

💡 Hint

Remember that path.resolve normalizes and joins paths, resolving '.' and '..' segments.

The path.resolve method joins the paths and normalizes them. The ./bar means 'bar' inside the current directory, so it becomes 'bar'. The final path is /foo/bar/baz.

❓ Predict Output

intermediate

What does path.resolve return when given an absolute path last?

What will this code output?

Node.js

import path from 'path';
console.log(path.resolve('foo', '/bar', 'baz'));

A "foo//bar/baz"

B "foo/bar/baz"

C "/foo/bar/baz"

D "/bar/baz"

💡 Hint

When an absolute path appears, path.resolve resets the base to that path.

When path.resolve encounters an absolute path, it discards previous segments and starts from that absolute path. Here, '/bar' is absolute, so the result is '/bar/baz'.

🔧 Debug

advanced

Why does this path.resolve call produce an unexpected path?

This code is intended to resolve to '/home/user/project/src/lib', but it outputs '/home/user/project/lib'. What is the cause?

Node.js

import path from 'path';
const base = '/home/user/project/src';
const result = path.resolve(base, '../lib');
console.log(result);

A Because '../lib' moves one directory up from 'src', so the result is '/home/user/project/lib'.

B Because path.resolve does not normalize '..' segments, so it keeps '../lib' literally.

C Because base should be relative, not absolute, for path.resolve to work correctly.

D Because path.resolve always appends paths without resolving '..' segments.

💡 Hint

Think about what '../lib' means relative to the base path.

The segment '../lib' means go up one directory from 'src' and then into 'lib'. So the resolved path is '/home/user/project/lib'.

❓ component_behavior

advanced

How does path.resolve behave with empty strings in arguments?

What will this code output?

Node.js

import path from 'path';
console.log(path.resolve('', '/foo', '', 'bar'));

A "/foo/bar"

B "foo/bar"

C "/foo//bar"

D "/foo"

💡 Hint

Empty strings are ignored in path.resolve arguments.

Empty strings are skipped. The absolute path '/foo' resets the base, and 'bar' is appended, resulting in '/foo/bar'.

📝 Syntax

expert

Which option causes a SyntaxError when importing and using path.resolve in Node.js ES modules?

Identify the code snippet that will cause a SyntaxError.

A import path from 'path'; console.log(path.resolve('/a', 'b'));

B const path = require('path'); console.log(path.resolve('/a', 'b'));

C import path from 'path'; console.log(path.resolve('/a', 'b')

D import { resolve } from 'path'; console.log(resolve('/a', 'b'));

💡 Hint

Look for missing or extra characters that break syntax.

Option C is missing a closing parenthesis in the console.log call, causing a SyntaxError.

Practice

1. What does path.resolve do in Node.js?

easy

A. It creates an absolute path from given path segments.

B. It reads the content of a file at a given path.

C. It deletes a file at a specified path.

D. It lists all files in a directory.

Solution

1. Step 1: Understand the purpose of path.resolve

   path.resolve combines path segments into a full absolute path.

2. Step 2: Compare with other options

   Reading, deleting, or listing files are unrelated to path.resolve's function.

3. Final Answer:

   It creates an absolute path from given path segments. -> Option A

4. Quick Check:

   path.resolve = absolute path creation [OK]

Hint: Remember: resolve means make full absolute path [OK]

Common Mistakes:

• Confusing path.resolve with file reading functions
• Thinking it deletes or lists files
• Assuming it returns relative paths

2. Which of the following is the correct syntax to use path.resolve to combine 'folder' and 'file.txt'?

easy

A. path.resolve('folder' + 'file.txt')

B. path.resolve['folder', 'file.txt']

C. path.resolve('folder', 'file.txt')

D. path.resolve('folder\\file.txt')

Solution

1. Step 1: Check correct function call syntax

   path.resolve is called with comma-separated arguments inside parentheses.

2. Step 2: Analyze each option

   path.resolve('folder', 'file.txt') uses correct syntax with separate arguments. path.resolve['folder', 'file.txt'] uses brackets incorrectly. path.resolve('folder' + 'file.txt') concatenates strings before passing to form 'folderfile.txt', which lacks a path separator and produces an incorrect path. path.resolve('folder\\file.txt') passes a single string using backslash as separator, which is incorrect on Unix systems and results in a wrong path.

3. Final Answer:

   path.resolve('folder', 'file.txt') -> Option C

4. Quick Check:

   Use commas inside parentheses for path.resolve [OK]

Hint: Use commas inside parentheses to combine paths [OK]

Common Mistakes:

• Using square brackets instead of parentheses
• Concatenating strings manually before passing
• Using backslash separators in path strings

3. Given the current directory is /home/user, what will path.resolve('docs', 'file.txt') return?

medium

A. /home/docs/file.txt

B. docs/file.txt

C. /docs/file.txt

D. /home/user/docs/file.txt

Solution

1. Step 1: Understand path.resolve behavior with relative paths

   When given relative paths, path.resolve resolves them against the current working directory.

2. Step 2: Combine current directory with given segments

   Current directory is /home/user, so resolving 'docs' and 'file.txt' results in /home/user/docs/file.txt.

3. Final Answer:

   /home/user/docs/file.txt -> Option D

4. Quick Check:

   Relative paths resolve from current directory [OK]

Hint: Relative paths resolve from current directory [OK]

Common Mistakes:

• Assuming path.resolve returns relative paths
• Confusing root directory with current directory
• Ignoring current working directory in resolution

4. What is wrong with this code snippet?

const path = require('path');
const fullPath = path.resolve['folder', 'file.txt'];
console.log(fullPath);

medium

A. Using square brackets instead of parentheses for function call.

B. Missing import of the path module.

C. Incorrect variable name for storing the path.

D. Using console.log instead of return.

Solution

1. Step 1: Identify syntax error in function call

   Function calls require parentheses (), not square brackets [].

2. Step 2: Check other parts of the code

   path module is imported correctly, variable name is valid, and console.log is fine for output.

3. Final Answer:

   Using square brackets instead of parentheses for function call. -> Option A

4. Quick Check:

   Function calls need parentheses () [OK]

Hint: Function calls always use parentheses, not brackets [OK]

Common Mistakes:

• Using brackets [] instead of parentheses ()
• Forgetting to import path module
• Confusing console.log with return

5. You want to get the absolute path to a file named config.json located in a folder settings inside your project root. Your current working directory can vary. Which code correctly ensures the absolute path regardless of where the script runs?

hard

A. path.resolve('settings', 'config.json')

B. path.resolve(__dirname, 'settings', 'config.json')

C. path.resolve(process.cwd(), 'settings/config.json')

D. path.resolve('./settings/config.json')

Solution

1. Step 1: Understand __dirname vs process.cwd()

   __dirname is the directory of the current script file, stable regardless of where the script is run from. process.cwd() is the current working directory, which can change.

2. Step 2: Analyze each option

   path.resolve(__dirname, 'settings', 'config.json') uses __dirname to build absolute path reliably. path.resolve('settings', 'config.json') and D depend on current working directory, which may vary. path.resolve(process.cwd(), 'settings/config.json') uses process.cwd() but with a string containing slash, which works but is less clear and can cause issues on some OS.

3. Final Answer:

   path.resolve(__dirname, 'settings', 'config.json') -> Option B

4. Quick Check:

   Use __dirname for stable absolute paths [OK]

Hint: Use __dirname to build absolute paths reliably [OK]

Common Mistakes:

• Using process.cwd() which can change unexpectedly
• Passing combined strings instead of separate parts
• Assuming relative paths always work