将查询PHP标记为JavaScript

I have that

JavaScript

flagQuery = session.reponseText;
alert(flagQuery);
flagQuery = JSON.parse(flagQuery);
contentElt.innerHTML = "valeur FLAG" + flagQuery;

My javascript must receive a flag sent from php.

The code above is the treatment of flag when it is received.

In my php I declare the variable flag to true. I want to treat this with Ajax, if it's possible. I don't know what to add in the PHP to get the flag in JavaScript?

I should prefer not to have to overload my code with a jQuery bookshop that I will use it for half a score line of code.

I assume want to access php value through ajax request. And you can do that liek below;

PHP: flag.php

<?php

$flag = "Your flag value";

echo $flag;

JS:

$.ajax({
    url: "flag.php",
    type: "get",
    success: function(data){
        alert("Flag value is: " + data);
    },
    error:function(){
        alert("Error occured!");
    }
});

Pure JS:

<script>
    function getFlagValue() {
        var xmlHttp;
        if (window.XMLHttpRequest) {
            xmlHttp = new XMLHttpRequest();
        } else {
            xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlHttp.onreadystatechange = function() {
            if (xmlHttp.readyState==4 && xmlHttp.status==200) {
                alert(xmlHttp.responseText);
            }
        }
        xmlHttp.open("GET","flag.php",true);
        xmlHttp.send();
    }
</script>

Hello. Try this and see if it's you need.

//PHP File
<?php
    echo json_encode(array("one","two"));
?>



//Js File
$.get("page.php", function(data){
 alert(data)
})