如何在javascript中访问php会​​话文件变量或数据？

Question

I have a php session file with name 'script1.php' which contains '$position' array. I want to access the value of this array in javascript file. I tried using this "$.get('script1.php', function ( data ) { var x = data;});" command and in 'data' variable i get {"Longitude": 12.917186, "Latitude": 50.831356} this kind of result , but I need to access only integer, how can i access the integer value. I have uploaded the php code. can someone please help me how to solve this problem i am new to the php.

<?php
// Start the session
session_name("mysession");
session_start();
if(isset($_SESSION["i"])){
$i = $_SESSION["i"];
}
else{
$i = 0;
}

// Set session variables
$position = array
(

 array(50.831118,  12.916574),
 array(50.831118,  12.918574), 
 array(50.831356,  12.917186),
 array(50.831604,  12.917834),
 array(50.831763,  12.918172),
 array(50.831916,  12.918603),
 array(50.832825,  12.918413),
 array(50.833206,  12.918303),
 array(50.832825,  12.918413),
 array(50.831916,  12.918603),
 array(50.831763,  12.918172),
 array(50.831604,  12.917834),
 array(50.831356,  12.917186),
 array(50.831118,  12.918574), 
 array(50.831118,  12.916574)

 );

 echo '{"Longitude": '.$position[$i][1].', "Latitude": '.$position[$i]
 [0].'}';

 $i++;
 if($i > count($position)){
 $i = 0;
 }

 $_SESSION["i"] = $i;

JavaScript code

$.get('script1.php', function ( data ) 
{
var x = data;
});

value stored in data variable {"Longitude": 12.917186, "Latitude": 50.831356}

Answer 1

Output the variable you want, remove the other echo.

echo json_encode(array('i' => $_SESSION["i"]));

Use getJSON and access the variable.

$.getJSON('script1.php', function ( data ) 
{
    console.log( data.i );
});

Sidenote: never manually build JSON like you have. Always create a data structure and then JSON encode it because that handles any escaping and special characters.

Answer 2

You can't get the session-variable in JS. You had to store the needed content in an (hidden) input field or use ajax for it

Answer 3

Rather than manually creating json, you should use phps json_encode on an array/object with the structure you require. You should also set the correct content type header, then jquery will automatically parse the result:

// Start the session
session_name("mysession");
session_start();
if(isset($_SESSION["i"])){
    $i = $_SESSION["i"];
}
else{
    $i = 0;
}

// Set session variables
$position = array
(

 array(50.831118,  12.916574),
 array(50.831118,  12.918574), 
 array(50.831356,  12.917186),
 array(50.831604,  12.917834),
 array(50.831763,  12.918172),
 array(50.831916,  12.918603),
 array(50.832825,  12.918413),
 array(50.833206,  12.918303),
 array(50.832825,  12.918413),
 array(50.831916,  12.918603),
 array(50.831763,  12.918172),
 array(50.831604,  12.917834),
 array(50.831356,  12.917186),
 array(50.831118,  12.918574), 
 array(50.831118,  12.916574)

 );

 $data = array(
     "lat"  => $position[$i][0],
     "long" => $position[$i][1], 
 );

 $i++;
 if($i > count($position)){
 $i = 0;
 }

 $_SESSION["i"] = $i;

header('Content-Type: application/json');
die(json_encode($data));

Then in your javascript you can access data as a regular js object:

$.get('script1.php', function(data){
    console.log(data.lat); //50.831118
    console.log(data.long); //12.916574
});