JSON Crash Course



In this video we will talk about JSON, JavaScript object literals and AJAX. Ill show you how to create JSON objects and arrays and also how to make an Ajax request to a .json file

CODE: Code for this video
http://traversymedia.com/downloads/json_sandbox.zip

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31 thoughts on “JSON Crash Course

  • February 13, 2019 at 02:49
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    Great Video. Thanks. Here you are using node.js and accessing the file from cmd. Is there a simpler way so that I can double click on the index.html file and see the output like an average user on chrome/firefox rather than accessing from cmd. If anybody could mention it would be a big help…

  • February 13, 2019 at 02:49
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    i get this until the part you went to json file. other than that it really is a great crashcourse. thanks

  • February 13, 2019 at 02:49
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    Let's say I'm using JSON files as a read-only data store of sorts. I have several MB of data that I don't want to pass over the wire all at once unless needed. I have it parsed into ~100 subdivisions of a few KB to a MB. I can have a one-page .js app pull data from these files (actually pull all the data from one whole file at a time, as demanded) based on query string and a few short look-up structures in the one page to translate the request.

    Bottom line, I've got a bunch of json files. I want them to be as short as possible. I like that I can address the data when I read it in with names for the indices, like file1.person.lastname, say. But, I sure as hell don't want to write "lastname": "Smith" 500 times in the file. That wastes bandwidth. Is there a way to define a type, then instantiate it 1000 times (like in an array of that type) in the same json file without the label, but simply by order, so I can save potentially tens of KB of transmission while still using the intuitive class member naming scheme in my one page (instead of using numeric indices as I fear I might have to)? I hope this is an intuitive question and I just don't know something I should but that is never covered in tutorials.

  • February 13, 2019 at 02:49
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    <body>

    <main>

    </main>

    <script>

    let renderOrderedList = ["Alpha", "Beta", "Gamma", "Delta", "Epsilon"];

    let output = ' ';

    for (let i = 0; i < renderOrderedList.length; i++) {

    output += '<ol>' +

    '<li>' + renderOrderedList[i] + '</li>' +

    '</ol>';

    }

    document.querySelector('main').innerHTML = output;

    </script>

    </body>

    I have above code which is working properly but when I try to use the function it wont work. Can anyone help me to solve the below code if possible?

    function renderOrderedList(){

    let output = ' ';

    for (let i = 0; i < renderOrderedList.length; i++) {

    output += '<ol>' +

    '<li>' + renderOrderedList[i] + '</li>' +

    '</ol>';

    }

    document.querySelector('main').innerHTML = output;

    }

    renderOrderedList(["Alpha", "Beta", "Gamma", "Delta", "Epsilon"]);

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