How to Loop Through Json Array and Get Specific Values

How to loop through JSON array and get specific values

in your loop:

for (x in myObj) {
 alert(x.car1);
}

x is the string value of key of your object. In order to get the car1 property of your nested object you can change your loop as:

for (x in myObj) {
 alert(myObj[x].car1);
}

It is also a good practice to use hasOwnProperty while using for-in loop it might also iterate over properties which are in your object's prototype chain.

for (x in myObj) {
 if (myObj.hasOwnProperty(x)) {
   alert(myObj[x].car1);
 }
}

Loop through JSON ARRAY and get value with node.js

In mean time I found a very easy way to get value from json array as follow:

Important NOTE (especially for the beginners):

If you are receiving response with http request, response is coming as a text string, so you need first to convert to JSON object as be abblle to extract values from array.

Full sample of the response is written on beginig of this thread.

http request code 
...
res.on("end", function (chunk) {
    var body = Buffer.concat(chunks);
    const response = JSON.parse(body.toString()); //convert string to JSON object

    var result = response.originalDetectIntentRequest.payload.contact.cId;
    console.log(result);
    return result;
 });

OR:

...
    var result = response.queryResult.outputContexts[0].name;
    console.log(result);
    return result;
  });

JSON - Iterate through JSONArray

Change

JSONObject objects = getArray.getJSONArray(i);

to

JSONObject objects = getArray.getJSONObject(i);

or to

JSONObject objects = getArray.optJSONObject(i);

depending on which JSON-to/from-Java library you're using. (It looks like getJSONObject will work for you.)

Then, to access the string elements in the "objects" JSONObject, get them out by element name.

String a = objects.get("A");

If you need the names of the elements in the JSONObject, you can use the static utility method JSONObject.getNames(JSONObject) to do so.

String[] elementNames = JSONObject.getNames(objects);

"Get the value for the first element and the value for the last element."

If "element" is referring to the component in the array, note that the first component is at index 0, and the last component is at index getArray.length() - 1.

I want to iterate though the objects in the array and get thier component and thier value. In my example the first object has 3 components, the scond has 5 and the third has 4 components. I want iterate though each of them and get thier component name and value.

The following code does exactly that.

import org.json.JSONArray;
import org.json.JSONObject;

public class Foo
{
  public static void main(String[] args) throws Exception
  {
    String jsonInput = "{\"JObjects\":{\"JArray1\":[{\"A\":\"a\",\"B\":\"b\",\"C\":\"c\"},{\"A\":\"a1\",\"B\":\"b2\",\"C\":\"c3\",\"D\":\"d4\",\"E\":\"e5\"},{\"A\":\"aa\",\"B\":\"bb\",\"C\":\"cc\",\"D\":\"dd\"}]}}";

    // "I want to iterate though the objects in the array..."
    JSONObject outerObject = new JSONObject(jsonInput);
    JSONObject innerObject = outerObject.getJSONObject("JObjects");
    JSONArray jsonArray = innerObject.getJSONArray("JArray1");
    for (int i = 0, size = jsonArray.length(); i < size; i++)
    {
      JSONObject objectInArray = jsonArray.getJSONObject(i);

      // "...and get thier component and thier value."
      String[] elementNames = JSONObject.getNames(objectInArray);
      System.out.printf("%d ELEMENTS IN CURRENT OBJECT:\n", elementNames.length);
      for (String elementName : elementNames)
      {
        String value = objectInArray.getString(elementName);
        System.out.printf("name=%s, value=%s\n", elementName, value);
      }
      System.out.println();
    }
  }
}
/*
OUTPUT:
3 ELEMENTS IN CURRENT OBJECT:
name=A, value=a
name=B, value=b
name=C, value=c

5 ELEMENTS IN CURRENT OBJECT:
name=D, value=d4
name=E, value=e5
name=A, value=a1
name=B, value=b2
name=C, value=c3

4 ELEMENTS IN CURRENT OBJECT:
name=D, value=dd
name=A, value=aa
name=B, value=bb
name=C, value=cc
*/

How do I loop through a JSON array?

You can use for..in loops on objects to get the keys and iterate over them. Objects don't implement the Iterable interface, so for...of doesnt work. And forEach is not a method on an object, but on an array.

const json = {
    "channels": {
        "main": {
            "id": "691548147922763825"
        },
        "creations": {
            "id": "700390086390448148"
        },
        "fanart": {
            "id": "691551615873843211"
        },
        "memes": {
            "id": "691549417173680148"
        }
    }
}

for( let key in json.channels ) {
  console.log( key, json.channels[key] )
}

const json = `[    {      "metadata": {        "id": "vvvvvvvvvvvvv",        "url": "cccccccccccccc",        "created_at": "2019-09-06T08:40:41Z",        "updated_at": "2019-09-06T13:25:46Z"      },      "entity": {        "name": "app1",        "b_enabled": false,        "d_url": "xxxxxs"      }    },      {      "metadata": {        "id": "vvvvvvvvvvccc",        "url": "cccccccccccccc",        "created_at": "2019-09-06T08:40:41Z",        "updated_at": "2019-09-06T13:25:46Z"      },      "entity": {        "name": "app2",        "b_enabled": false,        "d_url": "xxxxxs"      }    },      {      "metadata": {        "id": "vvvvvvvvvvddd",        "url": "cccccccccccccc",        "created_at": "2019-09-06T08:40:41Z",        "updated_at": "2019-09-06T13:25:46Z"      },      "entity": {        "name": "app3",        "b_enabled": false,        "d_url": "xxxxxs"      }    },      {      "metadata": {        "id": "vvvvvvvvvveee",        "url": "cccccccccccccc",        "created_at": "2019-09-06T08:40:41Z",        "updated_at": "2019-09-06T13:25:46Z"      },      "entity": {        "name": "app4",        "b_enabled": false,        "d_url": "xxxxxs"      }    },      {      "metadata": {        "id": "vvvvvvvvvvfff",        "url": "cccccccccccccc",        "created_at": "2019-09-06T08:40:41Z",        "updated_at": "2019-09-06T13:25:46Z"      },      "entity": {        "name": "app5",        "b_enabled": false,        "d_url": "xxxxxs"      }  }  ]`;
const result = JSON.parse(json)    .map(({ metadata: { id }, entity: { name } }) => {        return { [name]: id };    })    .reduce((prev, current) => {        const [name] = Object.keys(current);
        prev[name] = current[name];
        return prev;    }, {});
console.log(result);

var my_products = {    "products": [        {            "title": "Product 1",            "id": 001,            "stock_quantity": 0,            "in_stock": false        },        {            "title": "Product 2",            "id": 002,            "stock_quantity": 0,            "in_stock": false        },        {            "title": "Product 3",            "id": 003,            "stock_quantity": 1,            "in_stock": true        },        {            "title": "Product 4",            "id": 004,            "stock_quantity": 1,            "in_stock": true        }    ]};var filterData = [];$.each(my_products.products, function(){    if (this.in_stock && this.stock_quantity === 1) {        filterData.push(this);    }});console.log(filterData);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

public function select_from_fact_sighting($whereArray) {

    ...
    $jsonArray = json_decode($whereArray, true);
    $elementCount  = count($jsonArray);        

    $where = array();

    foreach($jsonArray as $row) {
        foreach($row as $key => $val) {
            $where[] = $key . " = " . $val;
        }
    }
    ....

var data = [
       {
        "digital_assets": [
          {
            "id": "AA001",
            "url": "https://via.placeholder.com/150"
          },
          {
            "id": "AA002",
            "url": "https://via.placeholder.com/150"
          }
        ]
      },
      {
        "products": [
          {
            "id": ["BB001", "AA001"],
            "ProductName": "PROD 485"
          },
          {
            "id": ["BB002","AA002"],
            "ProductName": "PROD 555"
          }
        ]
      }
    ]
let matchingIds = [];
let data_assetsObject = data.find(element => {
    return Object.keys(element).includes("digital_assets")
})
let productsObject = data.find(element => {
    return Object.keys(element).includes("products")
})
data_assetsObject["digital_assets"].forEach(da => {
  productsObject["products"].forEach(product => {
    if (product.id.includes(da.id)){
      matchingIds.push({
        url: da.url,
        productName: product.ProductName
      })
    }
  })
})
console.log(matchingIds);