[Solved] Given the following code snippet in a NestJS service, what will be the output if the token is valid? const token = jwt.sign({ userId: 123 }, 'secretKey', { expiresIn: '1h' }); const decoded = jwt.... | NestJS

NestJS - Authentication

Given the following code snippet in a NestJS service, what will be the output if the token is valid?

const token = jwt.sign({ userId: 123 }, 'secretKey', { expiresIn: '1h' });
const decoded = jwt.verify(token, 'secretKey');
console.log(decoded.userId);

Aundefined

Bnull

C123

DThrows an error

Step-by-Step Solution

Solution:

Step 1: Understand token creation and verification
The token is created with payload { userId: 123 } and signed with 'secretKey'.
Step 2: Verify token with the same secret
Verification returns the decoded payload, so decoded.userId is 123.
Final Answer:
123 -> Option C
Quick Check:
Valid token returns payload userId = 123 [OK]

Quick Trick: Verify returns original payload if token and secret match [OK]

Common Mistakes:

Expecting undefined or null instead of payload
Using wrong secret causing error
Confusing verify with sign

Master "Authentication" in NestJS

9 interactive learning modes - each teaches the same concept differently

Learn Why Deep Visual Try Challenge Project Recall Perf

More NestJS Quizzes

Given the following code snippet in a NestJS service, what will be the output if the token is valid?

Step 1: Understand token creation and verification

Step 2: Verify token with the same secret

Final Answer:

Quick Check:

Want More Practice?