如何从PHP中的嵌套json获取值

Question

I am a beginner to JSON and i'm trying to get values from a json string. For example i want to read the first "t":1443502800 and assing it to a variable $beginTime and the second "t":1443790800 assigned to a variable $endTime

{
  "op":"&",
  "c":[
       {
         "type":"date",
         "d":">=",
         "t":1443502800
       },
       {
         "type":"date",
         "d":"<",
         "t":1443790800
       }
     ],
  "showc":[true,true]
}

I would really appreciate any help :)

Edit code

foreach($rs2 as $record2)
    { 
      if( $record2->availability == '{"op":"&","c":[],"showc":[]}'){
        //skip, because the restriction date was not set for this attendance
      }
      else{
        //get the restriction date by making use of json                  
         $json_data = json_decode($record2->availability, true);
         echo $json_data['c'];
      }
    } 

Answer 1

The problem is you can't echo an array. You're trying to echo out $json_data['c'] , which is an array. Either return it or echo out what you need. For instance to echo out the start time use echo $json_data['c'][0]['t']

ORIGINAL ANSWER

You should use json_decode without true in the second variable. Then you have objects (started with braces { ) and arrays (started with square brackets [ ). You can then get the start and end times us

<?php
$string = '{
  "op":"&",
  "c":[
       {
         "type":"date",
         "d":">=",
         "t":1443502800
       },
       {
         "type":"date",
         "d":"<",
         "t":1443790800
       }
     ],
  "showc":[true,true]
}';
$json = json_decode($string);
echo "Start time: ".$json->c[0]->t;
echo "End time: ".$json->c[1]->t;

Here's an eval.in of it working - https://eval.in/441599

Answer 2

You were almost there. The full call should be to

$beginTime = $json_data['c'][0]['t'];

since $json_data['c'][0] is the array:

array (
    "type" => "date",
    "d" => ">=",
    "t" => 1443502800
),

The $endtime can be obtained in a similar manner:

$endTime = $json_data['c'][1]['t'];