Get json element javascript

JavaScript: How to Get JSON value by Key

We can see that this JSON data starts and ends with square brackets [. ] indicating that it is an array of data. So once it has been converted into a JS object we can access the elements by index (starting at 0) like so.

This will grab the first element

  "price":13300000,  "area":7420,  "bedrooms":4,  "bathrooms":2,  "stories":3,  "airconditioning":true > 

If you want to access each element of the array look at the looping section of this post

JSON value by Key

String index

If you need to access an object via a variable name then using a string to access the JSON data could be what you are looking for.

let price = firstObj["price"];  //to print it out  console.log("price of first object is: " + firstObj["price"]); 

price of first object is: 13300000 

Key Directly

If you know what the name will be ahead of time you can just use the name directly on the JS object

let price = firstObj.price;  //to print it out  console.log("price of first object is: " + firstObj.price); 

price of first object is: 13300000 

Unknown Keys

If you do not know the keys ahead of time you can get the keys then access the objects.

let firstKey = Object.keys(firstObj)[0]; let firstKeyValue = firstObj[firstKey];  //to print it out  console.log("price of first object is: " + firstObj[firstKey]); 

price of first object is: 13300000 

['price', 'area', 'bedrooms', 'bathrooms', 'stories', 'airconditioning'] 

so to get the first value price we will access it index 0

let firstKey = Object.keys(firstObj)[0]; 

so finally to get the value of price we can do the following

let firstKey = Object.keys(firstObj)[0]; let firstKeyValue = firstObj[firstKey]; 

Looping

If we wanted preform operations on all the elements in the array we have a few ways to do this. One of the most common is a forEach loop.

jsonData.forEach((element, i) =>   console.log("element: " + i + " is: " + JSON.stringify(element)) >); 

• jsonData = JS object
• forEach = forEach method to loop over data
• (…) =><..>; = arrow function, it;s a shorter way to write an anonymous function
  • (element, i) = arguments to the arrow function
    • element = the individual elements of the array will be given to this function as this argument
    • i = index of the current array object

    element: 0 is: element: 1 is: element: 2 is: element: 3 is: element: 4 is:

    Fun Surprise

    Congrats for making it all the way to the end! As a fun surprise you should inspect your js console (usually right click->inspect then find the console). You will see that this example ran while you where reading the page. Check the log output to see and have a great day.

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    Get Value From JSON Object In JavaScript

    Most of the data transaction between client and server is in form of JSON Object. We will see in this article how to get value from JSON object in JavaScript.

    In modern web applications, we use JSON to send data between client and server because it is the lightweight data-interchange format. JSON is also used to store data locally.

    Before sending JSON data to the server over an API we need to convert it into a string. In the same way server data you receive over API also need to be converted into a JSON object and then you can access the data.

    Let’s see how to get data from JSON object store locally or received over API in JavaScript.

    

    Get Value From JSON Object Stored Locally

    First, we will see how to get data from the JSON object stored locally in a variable.

    Let the data be following:

    The data shown above is JSON data which is stored in a variable named employee .

    Note : JSON data is a key: value pair separated by a comma, where the key is a string and value can be any valid data type like string, number, boolean, array, object, null, or undefined.

    To get value from the JSON object stored locally, we need to convert it into a JSON object first because JSON data is stored in string format.

    var data = ` < "employee": < "name": "John", "age": 30, "salary": 5000, "city": "New York", "skills": ["JavaScript", "CSS", "HTML"] >>`; // current data type is string 'data' console.log(typeof data); // convert data into JSON object var parsedData = JSON.parse(data); console.log(typeof parsedData); // get value from JSON object in JavaScript console.log(parsedData.employee.name, parsedData.employee.age, parsedData.employee.skills);

    The above code gets value from the JSON object stored locally and then prints the value in the console. The steps that we followed are:

    1. Convert JSON data into JSON object by using JSON.parse() method.
    2. The JSON string is now converted into the JSON object.
    3. Get value from JSON object by using dot notation .

    Looping Through JSON Object

    Above we get individual values from the JSON object. But we can also get all the values from the JSON object by using a for-in loop .

    var data = ` < "employee": < "name": "John", "age": 30, "salary": 5000, "city": "New York", "skills": ["JavaScript", "CSS", "HTML"] >>`; // convert data into JSON object var parsedData = JSON.parse(data); // looping through JSON object for(var key in parsedData.employee)

    The above code gets all the values from the JSON object and prints them in the console. The steps that we followed are:

    1. Converted JSON data into JSON object by using JSON.parse() method. Now it can be treated as a normal JavaScript object.
    2. Now, Loop through JSON object by using the for-in loop .

    Get Value Using Bracket Notation

    Above we accessed the value from the JSON object using dot notation but we can also access the value using bracket notation .

    In the bracket notation, you have to pass the key of the value you want to access as a string.

    Here is an example using bracket notation:

    var data = ` < "employee": < "name": "John", "age": 30, "salary": 5000, "city": "New York", "skills": ["JavaScript", "CSS", "HTML"] >>`; var parsedData = JSON.parse(data); console.log(parsedData.employee["name"]); console.log(parsedData.employee["age"]); console.log(parsedData.employee["skills"]);

    Data Received From Server

    JSON data that we receive from the server is in form of a string. So to get values from this data string first we need to convert it into a JSON object.

    Basically, there is no different process we will go through to get value. Again here we will use JSON.parse() method to convert a string into the JSON object and then will access the value.

    // data recieved from server // '>'; var data = JSON.parse('>'); // geting value console.log(data.employee.name); console.log(data.employee.age); console.log(data.employee.skills);

    Get Value from Local JSON File

    To get value first we need to read the local JSON file. We can do that by using the fetch() method.

    Pass the URL of the JSON file as a string to fetch() method, it will return a promise. The promise will resolve with the JSON data as a string.

    Here is a working example:

    // get data from local JSON file fetch('data.json') .then(response => response.json()) .then(data => < console.log(data.employee.name); console.log(data.employee.age); console.log(data.employee.salary); >)

    Same method you can use for any external JSON file too just pass the proper http URL.

    Conclusion

    This is the end of how to get value from JSON object in JavaScript. We have covered all ways that you can use different case scenarios. We have also covered how to get value from the local JSON files.

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    Get Value From JSON Object in JavaScript

    

    1. Parse JSON Object in JavaScript With the JSON.parse() Method
    2. Encode JSON Object in JavaScript

    When data are received from the web-server, the format is in JSON (data-interchange format for web apps). The format previews the data in a key:value pair and starts and ends with <> (for object) or [] (for arrays). Keys are always tend to be string and values can be string and other data-types also.

    This article will introduce how to get value from a JSON object in JavaScript.

    Parse JSON Object in JavaScript With the JSON.parse() Method

    Let us consider the following JSON object as the received data.

     "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  > > 

    The following code segment and image demonstrates the parsing method.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  var i;  for(i in data)  if(data[i]instanceof Object)  console.log(data[i]);  > > 

    

    Access Individual JSON Data With Dot (.) Operation in JavaScript

    As we have already parsed the data, now let’s extract the individual values for key:value pair with the dot ( . ) operation.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  console.log(data.employee.name); console.log(data.employee.favoriteColor[2]); console.log(data.employee.siblings); console.log(data.employee.siblings.Liza); 

    

    Access Individual JSON Data With Brackets [] in JavaScript

    This convention allows you to retrieve data in a similar way like and array accessing its data.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  console.log(data["employee"]["name"]); console.log(data["employee"]["favoriteColor"][2]); console.log(data["employee"]["siblings"]); console.log(data["employee"]["siblings"]["Emily"]); 

    

    Encode JSON Object in JavaScript

    Supposedly, you are to modify a JSON object and resend back to server, or the task is to convert JavaScript to JSON format. This is often helpful as it is difficult to edit large sized JSON object. So, after parsing the object and redirecting it to the same format we use the JSON.stringify method.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json); data.employee.name= "Riza Hawkeye"; const new_data = JSON.stringify(data); console.log(new_data); 

    

    Era is an observer who loves cracking the ambiguos barriers. An AI enthusiast to help others with the drive and develop a stronger community.

    Источник

    Get Value From JSON Object in JavaScript

    

    1. Parse JSON Object in JavaScript With the JSON.parse() Method
    2. Encode JSON Object in JavaScript

    When data are received from the web-server, the format is in JSON (data-interchange format for web apps). The format previews the data in a key:value pair and starts and ends with <> (for object) or [] (for arrays). Keys are always tend to be string and values can be string and other data-types also.

    This article will introduce how to get value from a JSON object in JavaScript.

    Parse JSON Object in JavaScript With the JSON.parse() Method

    Let us consider the following JSON object as the received data.

     "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  > > 

    The following code segment and image demonstrates the parsing method.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  var i;  for(i in data)  if(data[i]instanceof Object)  console.log(data[i]);  > > 

    

    Access Individual JSON Data With Dot (.) Operation in JavaScript

    As we have already parsed the data, now let’s extract the individual values for key:value pair with the dot ( . ) operation.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  console.log(data.employee.name); console.log(data.employee.favoriteColor[2]); console.log(data.employee.siblings); console.log(data.employee.siblings.Liza); 

    

    Access Individual JSON Data With Brackets [] in JavaScript

    This convention allows you to retrieve data in a similar way like and array accessing its data.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json);  console.log(data["employee"]["name"]); console.log(data["employee"]["favoriteColor"][2]); console.log(data["employee"]["siblings"]); console.log(data["employee"]["siblings"]["Emily"]); 

    

    Encode JSON Object in JavaScript

    Supposedly, you are to modify a JSON object and resend back to server, or the task is to convert JavaScript to JSON format. This is often helpful as it is difficult to edit large sized JSON object. So, after parsing the object and redirecting it to the same format we use the JSON.stringify method.

    const json = `  "employee":   "name": "Roy Mustang",  "age": 35,  "favoriteColor": ["Blue", "Black", "Purple"],  "siblings":   "Liza": 20, "Emily": 12  >  >  >`;  var data = JSON.parse(json); data.employee.name= "Riza Hawkeye"; const new_data = JSON.stringify(data); console.log(new_data); 

    

    Era is an observer who loves cracking the ambiguos barriers. An AI enthusiast to help others with the drive and develop a stronger community.

    Источник

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