[Solved] What is wrong with this JavaScript WebSocket client code on a Raspberry Pi? const socket = new WebSocket('ws://localhost:9000'); socket.send('Hello'); socket.onmessage = (msg) => console.log(msg.... | Raspberry Pi

Raspberry Pi - Web Server and API

What is wrong with this JavaScript WebSocket client code on a Raspberry Pi? const socket = new WebSocket('ws://localhost:9000'); socket.send('Hello'); socket.onmessage = (msg) => console.log(msg.data);

AUsing console.log incorrectly

BMissing event listener for errors

CIncorrect WebSocket URL

DSending message before connection is open

Step-by-Step Solution

Solution:

Step 1: Understand WebSocket connection timing
Messages must be sent only after the connection is open.
Step 2: Identify the error
Code sends 'Hello' immediately, before 'onopen' event, causing failure.
Final Answer:
Sending message before connection is open -> Option D
Quick Check:
Send only after onopen event [OK]

Quick Trick: Send messages only after onopen event fires [OK]

Common Mistakes:

MISTAKES

Sending messages immediately after creating socket
Ignoring connection open event
Assuming send queues messages automatically

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More Raspberry Pi Quizzes

What is wrong with this JavaScript WebSocket client code on a Raspberry Pi?

Step 1: Understand WebSocket connection timing

Step 2: Identify the error

Final Answer:

Quick Check:

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