Understanding the Different Types of API Calls: A Complete Guide

APIs are the core of modern apps, silently keeping things running as we binge-watch, buy meals, or book a taxi.

Have you ever thought how they work? Let’s examine how API calls work, what makes them tick, and why they’re important in modern apps.

What are API Calls?

In simple terms, API requests are your app’s way of asking the server, “Hey, can you give me this data?” / “Here’s new info — make it official!” API calls are requests sent from one app or server to another which allow data skill behind the scenes.

Importance of API Calls in Modern Applications

API calls, whether used to get user information or process payments, make apps dynamic and data-rich.

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Types of API Calls

01. GET Requests

• When to Use: Data is retrieved without any modifications.
• Syntax & Example: GET /users/123
• Common Use Cases: Viewing a user’s profile, and product listings.
• Pro Tip: Use GET for read-only actions. It’s quick and light on resources.

02. POST Requests

• Purpose: Sending data to the server to create a new entry.
• Syntax & Example: POST /users With user details in the request body.
• Use Cases: Creating accounts, and submitting forms.
• Pro Tip: Always validate input data on the server to avoid unintended data submissions.

03. PUT Requests

• Purpose: Updating existing data completely.
• Syntax & Example: PUT /users/123
• Use Cases: Updating a user profile.
• Pro Tip: PUT replaces the entire resource, so send all necessary data.

04. PATCH Requests

• Difference Between PUT and PATCH: PATCH supports partial updates (which is suitable for changing a single field).
• Syntax & Example: PATCH /users/123 With only fields that need updating.
• Use Cases: Changing status, updating a single field.
• Pro Tip: PATCH is ideal for doing fast changes while maintaining unaltered fields.

05. DELETE Requests

• Purpose: Removing data.
• Syntax & Example: DELETE /users/123
• Use Cases: Delete records such as an expired account or an item from a cart.
• Pro Tip: Use with caution; once data is gone, it’s gone!

06. OPTIONS and HEAD Requests

• Explanation of OPTIONS: Checks what methods a server allows (handy for CORS).
• Explanation of HEAD: Retrieves metadata without loading the full content.
• Use Cases: Checking server capabilities, and lightweight requests for meta-info.

Anatomy of an API Request and Response

• Structure of a URL in API Calls: Example — https://api.example.com/users?active=true
• Query Parameters vs. Path Parameters: Query parameters add search conditions, while path parameters identify resources.
• HTTP Status Codes: Knowing what each means, like 200 (Success) or 404 (Not Found).
• Headers and Authentication: Use Bearer tokens, API keys, etc., for secure requests.

RESTful vs. GraphQL API Calls

• Key Differences: REST fetches whole data sets; GraphQL allows precise queries.
• Use Cases: REST is great for simplicity, and GraphQL shines in complex queries.
• Example: REST endpoint for users vs. GraphQL query for specific user data.
• Pro Tip: Choose GraphQL for efficiency in high-data projects.

API Call Optimization Techniques

• Reducing Latency: Use HTTP/2, compression, and efficient headers.
• Error Handling: Design clear error messages, e.g., “Failed to retrieve data.”
• Pro Tip: Avoid redundant API calls; plan efficient workflows to keep loads light.

Practical Use Cases of API Calls in Different Industries

1. E-commerce: Fetching products, and managing inventory.
2. Social Media: Posting and retrieving feeds.
3. Fintech: Processing payments securely.
4. Entertainment: Streaming recommendations and managing user profiles.

Common Mistakes and Pitfalls with API Calls

• Overusing Network Requests: Repeating API calls needlessly.
• Ignoring Error Codes: Error handling is essential for user experience.
• Not Validating or Sanitizing Responses: Prevents security vulnerabilities.

Testing and Debugging API Calls

• Using Tools like Postman and Insomnia: Simulate requests, and view responses.
• Mocking APIs for Testing: Use mock data to test without live data.
• Debugging Tips: Log requests and responses to troubleshoot effectively.

Conclusion

APIs are at the heart of today’s digital ecosystems, powering almost every app we use. Understanding different types of API calls helps you build apps that are efficient, reliable, and secure.

So whether you’re crafting a new feature or debugging an issue, remember that a solid grasp of API calls can take you a long way.

Originally published on medium.com.