CODEWITHSUNDEEP
javascript
Prime
Prime

Reputation: 39

Fetch total no of arrays instead of data from api

I am trying to fetch the total number of arrays of validators (example-1038) from JSON file using this code but it is not working.

What is wrong with my code?

let fetchRes = fetch("https://avax.dev/data/validators.json"); 

// fetchRes is the promise to resolve 
// it by using.then() method 
fetchRes
 .then(res => res.json())
 .then(d => {
     console.log(d)
     
     let len = Object.keys(validators).length;

     console.log(len);
 });

Upvotes: 0

Views: 95

Answers (3)

Kapil Sharma
Kapil Sharma

Reputation: 179

In your code, "d" is an object. Inside the object "validators" is a key with array as value (key: value pair). So in order to access the validators length you will have to do "d.validators.length".

let fetchRes = fetch("https://avax.dev/data/validators.json"); 

   
fetchRes.then(res => res.json())
.then(d => { 
    console.log(d);
    //get the array length using d.validators.length
    console.log(d.validators.length)

})

Upvotes: 1

Usman Sabuwala
Usman Sabuwala

Reputation: 898

I formatted the code too.

You were trying to access the validators array outside .then. So the data (d) we get back is what I am using to get the validators.

let fetchRes = fetch("https://avax.dev/data/validators.json");

// fetchRes is the promise to resolve

// it by using.then() method

fetchRes
  .then((res) => res.json())
  .then((d) => {
    console.log(d);
    let len = d.validators.length;
    console.log(len);
  });

Upvotes: 0

Hans Krohn
Hans Krohn

Reputation: 433

You currently are trying to get the length of the validators field outside the promise resolution. What is actually happening is that these lines

var len = Object.keys(validators).length;
console.log(len);

run before the console.log(d). On top of this the variable d is not available outside of the .then()

to fix this just move the code inside the .then()

fetchRes
.then(res => res.json())
.then(d => {    
    const length = d.validators.length;
    console.log(length);
})

Upvotes: 0

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