How to console the PHP echo in my javascript? - php

Question

I can not get the PHP echo in my Ajax.
This is my test01.html code:
In my HTML code, I quote the jQuery, and I bind the event in my "sub01" button, I use Ajax provide the POST request:
$(".sub01").bind("click", function() {
$.ajax({
type: "POST",
url: "cms/test01.php?action=test01",
dataType: "json",
data: {
"var_01": "var_01_value",
"var_02": "var_02_value",
},
success: function(response) {
console.log(response) // there I want to console the response from PHP.
}
})
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div>
<form>
<input type="text" value="var_01">
<input type="text" value="var_02">
<input id="sub01" type="submit" value="click me!">
</form>
</div>
And this is my PHP test01.php code:
in my PHP code I want to echo the $_POST, then I want the AJAX code get the response.
<?php
echo $_POST;
I want the code
success: function(response) {
console.log(response) // there I want to console the response from PHP.
}
shows the PHP echo, but there console nothing.

Answer 1

Problem 1
You never call your JS function
$(".sub01").bind
You are binding to the click event of elements with the class sub01.
<input id="sub01" type="submit" value="click me!">
Your button doesn't have that class!
Aside: bind is deprecated in favour of on.
$("#sub01).on("click" ....
Problem 2
You aren't letting the JS run
Since you are (trying) to run the JS when a submit button is clicked, the form is submitting.
The browser is leaving the page before the Ajax response comes back and triggers the success function.
You need to prevent the default behavior of the submit button.
$("#sub01").on("click", function (event) {
event.preventDefault();
// etc
});
Problem 3
You aren't parsing the response correctly
You said dataType: "json", which means "Tell the server I only Accept JSON and ignore the Content-Type and parse the response as JSON regardless".
Since the server is not responding with JSON, the attempt to parse the response fails and it errors.
Option 1
Remove dataType: "json".
This will process the response as invalid HTML (because PHP sends Content-Type: text/html by default).
Then you will echo the response (which is Array … probably not the response you want PHP to send though).
Option 2
Change the PHP so it responds with JSON
<?php
header("Content-Type: application/json");
echo json_encode($_POST, JSON_PRETTY_PRINT);

Answer 2

You need to output a json.
header('Content-Type: application/json');
echo json_encode($_POST);