Can i use json

Throws a TypeError "cyclic object value" exception when a circular reference is found. Boolean , Number , and String objects are converted to the corresponding primitive values during stringification, in accord with the traditional conversion semantics. If any such values are encountered during conversion they are either omitted when found in an object or changed to null when found in an array. All Symbol -keyed properties will be completely ignored, even when using the replacer function.

Thus, they are treated as strings. The numbers Infinity and NaN , as well as the value null , are all considered null. The replacer parameter can be either a function or an array.

It should return the value that should be added to the JSON string, as follows: If you return a Number , String , Boolean , or null , the stringified version of that value is used as the property's value. If you return a Function , Symbol , or undefined , the property is not included in the output.

If you return any other object, the object is recursively stringified, calling the replacer function on each property. The space argument may be used to control spacing in the final string. If it is a number , successive levels in the stringification will each be indented by this many space characters up to If it is a string , successive levels will be indented by this string or the first ten characters of it.

This has led to more responsive web pages, and sounds exciting, but it is beyond the scope of this article to teach it in much more detail. Here we are storing the response to our request available in the response property in a variable called superHeroes ; this variable now contains the JavaScript object based on the JSON!

We have wrapped the code in an event handler that runs when the load event fires on the request object see onload — this is because the load event fires when the response has successfully returned; doing it this way guarantees that request. Now that we've retrieved the JSON data and converted it into a JavaScript object, let's make use of it by writing the two functions we referenced above.

First of all, add the following function definition below the previous code:. We then do a very similar operation with a paragraph: create it, set its text content and append it to the header.

The only difference is that its text is set to a concatenated string containing both the homeTown and formed properties of the object. Next, add the following function at the bottom of the code, which creates and displays the superhero cards:. To start with, we store the members property of the JavaScript object in a new variable. This array contains multiple objects that contain the information for each hero.

Next, we use a for loop to loop through each object in the array. For each one, we:. Note: If you are having trouble getting the example to work, try referring to our heroes-finished. You should also refer back to our JavaScript object basics article for more information on dot and bracket notation.

But sometimes we aren't so lucky — sometimes we receive a raw JSON string, and we need to convert it to an object ourselves. And when we want to send a JavaScript object across the network, we need to convert it to JSON a string before sending. Luckily, these two problems are so common in web development that a built-in JSON object is available in browsers, which contains the following two methods:.

You can see the first one in action in our heroes-finished-json-parse. Inside the object, we can declare any number of properties using a "name": "value" pairing, separated by commas. To access the information stored in jason , we can simply refer to the name of the property we need. For instance, to access information about me, we could use the following snippets:.

A slightly more complicated example involves storing two people in one variable. To do this, we enclose multiple objects in square brackets, which signifies an array. For instance, if I needed to include information about myself and my brother in one variable, I might use the following:.

To access this information, we need to access the array index of the person we wish to access. For example, we would use the following snippet to access info stored in family :. NOTE: This is beneficial if it will be necessary to loop through stored information, as it lends itself to a for loop with an automatically incrementing value.

Another way to store multiple people in our variable would be to nest objects.