Fetch API for POST requests in React Native - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the Fetch API in React Native?

The Fetch API is used to make network requests, such as getting or sending data to a server, in React Native apps.

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How do you specify a POST request using Fetch API?

You set the method property to 'POST' inside the options object passed to fetch, like: fetch(url, { method: 'POST' }).

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Why do we include headers like 'Content-Type': 'application/json' in a POST request?

Headers tell the server what kind of data is being sent. 'Content-Type': 'application/json' means the data is in JSON format.

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How do you send data in the body of a POST request using Fetch API?

You add a 'body' property with a JSON string, created by JSON.stringify(yourData), inside the fetch options.

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What does the fetch function return and how do you handle the response?

Fetch returns a Promise. You use .then() to handle the response and convert it to JSON with response.json(), then use the data.

Which option correctly sets up a POST request with Fetch API?

A fetch(url, { method: 'POST', body: JSON.stringify(data) })

B fetch(url, { method: 'GET', body: JSON.stringify(data) })

C fetch(url, { body: data })

D fetch(url)

To send data with POST, you must set method to 'POST' and include the body as a JSON string.

What header should you add to tell the server you are sending JSON data?

A 'Accept': 'text/html'

B 'Content-Type': 'application/json'

C 'Authorization': 'Bearer token'

D 'Content-Length': '100'

'Content-Type': 'application/json' tells the server the data format is JSON.

What does fetch() return when you call it?

A A Promise

B A JSON object

C An array

D A string

Fetch returns a Promise that resolves to the response object.

How do you convert the fetch response to usable JSON data?

A response.toJSON()

B JSON.parse(response)

C response.json()

D response.text()

response.json() is a method that returns a Promise resolving to the parsed JSON.

Which is a correct way to handle errors in a fetch POST request?

A Use alert() only

B Ignore errors

C Use try/catch without async

D Use .catch() after .then()

You handle fetch errors by adding a .catch() block after the .then() chain.

Explain how to make a POST request using Fetch API in React Native.

Think about how you tell the server what you are sending and how you handle the reply.

Describe the steps to send JSON data to a server and receive a JSON response using Fetch API.

Focus on both sending and receiving JSON data.