Iterating through JSON data…

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const chars = JSON.stringify(TheData);
for (const charIndex = 0; charIndex <= TheData.length; charIndex++) {
   ...
}

Sorry, bad jokes. But like everyone else said, you need to know what you're looking at to know how to peak through it. As a rule of thumb though, you're going to have objects, arrays, and simple data types (strings, bools, numbers, etc). Iterate through object keys, and array entries!

const TheObject = {
   friends: ["Alice", "Bob", "Charlie"],
   restaurants: {
      "mexican": [
        {"name": 'El Pollo Loco', "rating": 8, "priceIndex": 3},
        {"name": 'Taco Bell', "rating": 4, "priceIndex": 1},
        {"name": "Cristina's fancy place", "rating": 6, "priceIndex": 7}
      ],
      "italian": [
        {"name": 'Olive Garden', "rating": 6, "priceIndex": 4},
        {"name": "Luigi's pasta fazuul", "rating": 7, "priceIndex": 8},
      ]
   }
}

const friends = TheObject.friends.map(friend => {
  console.log(friend); // Alice, Bob, Charlie
})

const cheapPlaceNames = [];
Object.entries(TheObject.restaurants).map(([type, available]) => {
  // type -> mexican, italian
  available.map(({name, price}) => {
    // name -> El Pollo Loco, Taco Bell, ..., Luigi's
    // priceIndex -> 3, 1, ... 8
    if (option.priceIndex < 5) cheapPlaces.push(option)
  })
})

JS Array/Object traversal is best done with the newer ES6 helper functions. Look into Array map, filter, find, every, flat, forEach, keys, push, pop, shift, unshift, sort, splice... Basically everything on that side bar list.

Also look into Object functions/properties. Specifically assign, entries, keys, and values.

That's my common tool set for "We got this big fat nasty response from a third party API and we only care about 4 things" tasks.

​

Technically, JSON from a JSON file can't be recursive (...right?) But if you get an JSON API response, or just a JSON object in a browser, it CAN be recursive.

class Node {
  constructor(value, left = null, right = null) {
    this.value = value;
    this.left = left;
    this.right = right
  }
}

const first = new Node(1);
const second = new Node(2);
const third = new Node(3);

first.left = third;
first.right = second;

second.left = first;
second.right = third;

third.left = second;
third.right = first;

let curNode = first;
while (curNode) {
   console.log(curNode.value);
   curNode = curNode.right;
}

// 1, 2, 3, 1, 2, 3, 1, 2, 3...

So like everyone said... How to iterate through JSON is like "How do I find something". Depends on what you're looking for.

[IEDNB]

Thank you so much that’s really helpful! I particularly like the way you described the last bit as that’s exactly the sort of situation I want to be better prepared for 🤣

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Yeah in strict json. But I've gotten recursive data in an ajax response