Problem with fetching body of a restful api?-CodePudding

I'm learning how to properly fetch an API in javascript into my code, and I am having some issues retrieving specific parts of the body. Ideally, I want to save the setup and punchline part of the body to be saved into a variable to be used later.

I wrote this:

fetch("https://dad-jokes.p.rapidapi.com/random/joke", {
    "method": "GET",
    "headers": {
        "x-rapidapi-host": "dad-jokes.p.rapidapi.com",
        "x-rapidapi-key": "79142f2e8cmsh903cd5752a9ee77p1166f8jsnb9c812f77793"
    }
})
.then(res => res.json())
.then(data => console.log(data));

which returns this:

{
{
  success: true,
  body: [
    {
      _id: "60dd3699212bcedc7b8720a1",
      setup: "I saw a poster today for a free concert for those working in public health. It said 'Frontline Only'...",
      punchline: "Weird. I would've thought they'd fill the whole venue.",
      type: "health",
      likes: [],
      author: { name: "unknown", id: null },
      approved: true,
      date: 1618108661,
      NSFW: false
    }
  ]
}

As stated above, my desire here is to save the setup and punchline of the joke to a variable to be posted separately. How should I go about this? Thanks.

CodePudding user response：

You can define the variables for the data you wish to fetch before hand. As 'data.body' is an array, one element in length, we have to access it using data.body[0]. Then you can assign the variables using the names of the elements e.g 'body[0].setup'.

This should work! :-)

var setup;
var punchline;

var data = await fetch("https://dad-jokes.p.rapidapi.com/random/joke", {
    "method": "GET",
    "headers": {
        "x-rapidapi-host": "dad-jokes.p.rapidapi.com",
        "x-rapidapi-key": "79142f2e8cmsh903cd5752a9ee77p1166f8jsnb9c812f77793"
    }
})

setup = data.body[0].setup; 
punchline = data.body[0].punchline; 
console.log(data); 
console.log(setup); 
console.log(punchline);

CodePudding user response：

I think the problem you're having is that fetch() is asynchronous. So, code that appears in the program on a line after the fetch statement will execute before your then() statement. A simple example:

runsFirst();
fetch.then(() => runsThird());
runsSecond();

So when you attempt to log these values outside your then() statement, you are actually logging them before they've been set. To actually get the values, you need:

var setup;
var punchline;

fetch("https://dad-jokes.p.rapidapi.com/random/joke", {
    "method": "GET",
    "headers": {
        "x-rapidapi-host": "dad-jokes.p.rapidapi.com",
        "x-rapidapi-key": "79142f2e8cmsh903cd5752a9ee77p1166f8jsnb9c812f77793"
    }
})
.then(res => res.json())
.then(function (data){
    //Logs data
    setup = data.body[0].setup; 
    punchline = data.body[0].punchline; 
    console.log(setup, punchline); 
});

//Logs undefined
console.log(setup, punchline);

If you find this syntax confusing, you can use async/await, and then lines will more or less execute in the order they are written, though the browser support is not quite as good.