Why HTTP methods define intent in Rest API

Introduction

HTTP methods tell the server what action you want to do with data. They make your request clear and help the server respond correctly.

When you want to get information from a website or app.

When you want to add new data to a server, like creating a new user.

When you want to change existing data, like updating a profile.

When you want to remove data, like deleting a post.

When you want to check if a resource exists without changing it.

Syntax

Rest API

GET /resource
POST /resource
PUT /resource
DELETE /resource
PATCH /resource

GET asks for data without changing it.

POST sends new data to the server.

PUT replaces existing data with new data.

DELETE removes data from the server.

PATCH updates parts of existing data.

Examples

This asks the server to send back all users.

Rest API

GET /users
// Retrieves a list of users

This sends new user data to the server to create a user.

Rest API

POST /users
{
  "name": "Alice"
}
// Adds a new user named Alice

This replaces the user data with new information.

Rest API

PUT /users/1
{
  "name": "Alice Smith"
}
// Updates user with ID 1

This tells the server to delete the user.

Rest API

DELETE /users/1
// Removes user with ID 1

Sample Program

This program shows how GET fetches data and DELETE removes it using HTTP methods.

Rest API

import requests

# URL of the API
url = 'https://jsonplaceholder.typicode.com/posts/1'

# GET request to fetch data
response_get = requests.get(url)
print('GET status:', response_get.status_code)
print('GET data:', response_get.json())

# DELETE request to remove data
response_delete = requests.delete(url)
print('DELETE status:', response_delete.status_code)

Important Notes

Using the right HTTP method helps servers understand your request clearly.

GET requests should never change data on the server.

POST, PUT, PATCH, and DELETE change data in different ways.

Summary

HTTP methods show what you want to do with data.

GET gets data, POST adds, PUT/PATCH update, DELETE removes.

Choosing the right method makes your API calls clear and safe.

Practice

1. Which HTTP method is used to retrieve data from a server without changing it?

easy

A. GET

B. POST

C. DELETE

D. PUT

Solution

1. Step 1: Understand the purpose of HTTP methods

   GET is designed to request data without modifying it, making it safe and idempotent.

2. Step 2: Match method to action

   Since the question asks for retrieving data without changes, GET fits perfectly.

3. Final Answer:

   GET -> Option A

4. Quick Check:

   Retrieve data = GET [OK]

Hint: GET is for reading data, no changes made [OK]

Common Mistakes:

• Confusing GET with POST
• Thinking DELETE retrieves data
• Using PUT to fetch data

2. Which of the following is the correct syntax to update a resource using HTTP methods?

easy

A. GET /resource/123

B. DELETE /resource/123

C. POST /resource/123

D. PUT /resource/123

Solution

1. Step 1: Identify the method used for updating

   PUT is the HTTP method used to update or replace a resource at a specific URL.

2. Step 2: Check the syntax correctness

   PUT /resource/123 correctly targets the resource with ID 123 for update.

3. Final Answer:

   PUT /resource/123 -> Option D

4. Quick Check:

   Update resource = PUT [OK]

Hint: PUT updates existing resources fully [OK]

Common Mistakes:

• Using GET to update
• POST is for creating, not updating
• DELETE removes, not updates

3. What will be the expected result of this HTTP request?

POST /users
{
  "name": "Alice",
  "age": 30
}

medium

A. Create a new user named Alice

B. Delete user Alice

C. Update existing user Alice's age

D. Retrieve user data for Alice

Solution

1. Step 1: Identify the HTTP method used

   POST is used to create new resources on the server.

2. Step 2: Analyze the request body

   The JSON data contains user details, indicating creation of a new user named Alice.

3. Final Answer:

   Create a new user named Alice -> Option A

4. Quick Check:

   POST with data = Create new resource [OK]

Hint: POST adds new data, not fetch or delete [OK]

Common Mistakes:

• Thinking POST retrieves data
• Confusing POST with PUT for update
• Assuming POST deletes data

4. You want to remove a user with ID 45 using an HTTP request, but the request POST /users/45 is not working. What is the correct method to use?

medium

A. GET

B. PUT

C. DELETE

D. PATCH

Solution

1. Step 1: Understand the intent of the request

   The goal is to remove (delete) a user, so the method must express deletion.

2. Step 2: Choose the HTTP method for deletion

   DELETE is the standard method to remove a resource identified by a URL.

3. Final Answer:

   DELETE -> Option C

4. Quick Check:

   Remove resource = DELETE [OK]

Hint: DELETE removes resources, POST does not [OK]

Common Mistakes:

• Using POST to delete
• Confusing PATCH with DELETE
• Trying GET to remove data

5. You have an API where PATCH /profile/123 updates only the email field of a user profile, while PUT /profile/123 replaces the entire profile. Why is it important to choose PATCH over PUT when updating just one field?

hard

A. PATCH is faster because it sends less data

B. PUT can accidentally erase other fields if not included

C. PATCH creates a new profile instead of updating

D. PUT is only for deleting resources

Solution

1. Step 1: Understand the difference between PUT and PATCH

   PUT replaces the entire resource, so missing fields get erased. PATCH updates only specified fields.

2. Step 2: Analyze the risk of using PUT for partial updates

   If you use PUT but omit some fields, those fields may be removed unintentionally.

3. Final Answer:

   PUT can accidentally erase other fields if not included -> Option B

4. Quick Check:

   Partial update safe = PATCH, full replace risk = PUT [OK]

Hint: Use PATCH for partial updates to avoid data loss [OK]

Common Mistakes:

• Thinking PATCH creates new resource
• Believing PUT only deletes
• Assuming PATCH sends no data