JavaScript AJAX Basics (retiring) Programming AJAX Parsing JSON Data

Miguel Nunez
Miguel Nunez
3,266 Points

How can I for loop this json example in AJAX?

How can I for loop a JSON object in AJAX. I asked this question on stack overflow but they are to strict and very sensitive people. I don't know how to add a code example on this site so here's the link https://stackoverflow.com/questions/45555534/how-can-i-for-loop-this-json-object-in-this-ajax-situation-not-a-duplicate?noredirect=1#comment78071136_45555534

GREGORY ASSASIE
GREGORY ASSASIE
3,898 Points

There is a viable response on your stackOverflow post. you have to parse the json before you can loop over it.

JSON.parse()
//this is the method you use

2 Answers

Steven Parker
Steven Parker
174,022 Points

At the link provided, there are two answers with two different loops that seem like they would do the job. Do they work for you?

And they both seem to be helpful. I didn't see any responses that appeared to be "strict and very sensitive ". I did notice that the question itself was downvoted a few times, but that might be a reaction to suggesting that many participants "suck at explaining" and asking for "no lazy people". I think the fact that folks answered anyway serves as a testament of the general good will in the community.

Miguel Nunez
Miguel Nunez
3,266 Points

Well yeah I love the methods from both of the guys the one that I like the most and it's the easiest to understand and is closer to the tree house ways of doing thing was this guys code that I added to my file. But I notice his code had unlikable effects. I notice the button didn't disappear and every time I keep pressing the button it keeps generating the same JSON contents. In other words I want the JSON contents to show one time and I want the button to disappear after I press it so how can I do that?

alt text

Here's the AJAX file and JSON file ignore the three dots at the end of the JSON file.

<!--THE AJAX FILE-->
<!DOCTYPE html>
<html>
<body>

<div id="demo">
<button id="bg" type="button" onclick="x()">Change Content</button>
</div>

<script>
function x() {
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function () {
if (xhr.readyState == 4) {
var employees = JSON.parse(xhr.responseText);
for(var i=0;i<employees.length;i++){
    employee = employees[i];
    document.getElementById("demo").innerHTML += '<br>' + employee.name;

}
}
};
xhr.open("GET", "json_example_2.json", true);
xhr.send();
}
</script>

</body>
</html>

<!--THE JSON FILE-->
[
{
        "name": "Adam",
        "age": 21,
        "interest": ["food", "relaxing"]
    },

    {
        "name": "Bob",
        "age": 22,
        "interest": ["working out", "sleeping"]
    },

    {
        "name": "Cane",
        "age": 23,
        "interest": ["football", "vide games"]
    }
    ]
          ```
Steven Parker
Steven Parker
174,022 Points

Miguel Nunez — I like the cute animation, how did you make that?

One easy way to make the button disappear is to set the display attribute to none. Expand the HTML to pass a reference to itself:

<button type="button" onclick="x(this)">Change Content</button>

And then in the script:

function x(btn) {              // take the button argument
  // ... do the other stuff ...
  btn.style.display = "none";  // then make button vanish
}
GREGORY ASSASIE
GREGORY ASSASIE
3,898 Points

A quick fix for this is to remove all the textContent first each time, before the actually request is made.

<!--THE AJAX FILE-->
<!DOCTYPE html>
<html>
<body>

<div id="demo">
<button id="bg" type="button" onclick="x()">Change Content</button>
</div>

<script>
function x() {

var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function () {
if (xhr.readyState == 4) {
var employees = JSON.parse(xhr.responseText);
 document.getElementById("demo").innerHTML = "";
for(var i=0;i<employees.length;i++){
    employee = employees[i];
    document.getElementById("demo").innerHTML += '<br>' + employee.name;
}
}
};
xhr.open("GET", "json_example_2.json", true);
xhr.send();
}
</script>

</body>
</html>

<!--THE JSON FILE-->
[
{
        "name": "Adam",
        "age": 21,
        "interest": ["food", "relaxing"]
    },

    {
        "name": "Bob",
        "age": 22,
        "interest": ["working out", "sleeping"]
    },

    {
        "name": "Cane",
        "age": 23,
        "interest": ["football", "vide games"]
    }
    ]
          ```