HTTP Methods

HTTP methods, also known as HTTP verbs, define the actions to be performed on a specific resource. These methods are the building blocks of HTTP communication, allowing clients to interact with servers to retrieve, create, update, or delete resources. Below are the most commonly used HTTP methods:

1. GET

The GET method is used to retrieve data from a server without modifying it. It is a read-only operation, making it safe and idempotent.

• Use Case: Fetching a webpage, retrieving data from an API.
• Characteristics:
  • No request body (parameters are usually passed in the URL).
  • Cached by browsers and search engines for performance.
• Example:

  
  GET /api/users HTTP/1.1
  Host: example.com
  
      

2. POST

The POST method is used to send data to the server to create a new resource. Unlike GET, it has a request body that contains the data to be sent.

• Use Case: Submitting a form, creating a new database entry.
• Characteristics:
  • Data is sent in the request body.
  • Not cached by browsers.
• Example:

  
  POST /api/users HTTP/1.1
  Host: example.com
  Content-Type: application/json
  
  {
    "name": "John Doe",
    "email": "john@example.com"
  }
  
      

3. PUT

The PUT method is used to update an existing resource or create a resource if it does not exist. It replaces the entire resource with the new data provided in the request body.

• Use Case: Updating user profile details, replacing a file.
• Characteristics:
  • Idempotent (multiple identical requests have the same effect).
  • Data is sent in the request body.
• Example:

  
  PUT /api/users/1 HTTP/1.1
  Host: example.com
  Content-Type: application/json
  
  {
    "name": "Jane Doe",
    "email": "jane@example.com"
  }
  
      

4. DELETE

The DELETE method is used to remove a resource from the server. Once deleted, the resource cannot be retrieved unless recreated.

• Use Case: Deleting a user account, removing an item from a database.
• Characteristics:
  • Idempotent (multiple identical requests have the same effect).
  • Usually does not have a request body.
• Example:

  
  DELETE /api/users/1 HTTP/1.1
  Host: example.com
  
      

5. PATCH

The PATCH method is used to make partial updates to a resource. Unlike PUT, it does not replace the entire resource, but only the fields specified in the request body.

• Use Case: Updating a user's email address without changing their name.
• Characteristics:
  • Partially updates the resource.
  • May or may not be idempotent (depends on the implementation).
• Example:

  
  PATCH /api/users/1 HTTP/1.1
  Host: example.com
  Content-Type: application/json
  
  {
    "email": "newemail@example.com"
  }
  
      

Summary

Understanding HTTP methods is crucial for building APIs and web applications. Each method serves a distinct purpose, and using them appropriately ensures clarity and consistency in communication between clients and servers.