PHP是怎么返回json格式的数据

header('Content-type: text/json');

< ?php
header('Content-type: text/json');

$fruits = array (
    "fruits"  => array("a" => "orange", "b" => "banana", "c" => "apple"),
    "numbers" => array(1, 2, 3, 4, 5, 6),
    "holes"   => array("first", 5 => "second", "third")
);
echo json_encode($fruits);
?>

$(function(){
     $('#send').click(function() {
          $.getJSON('http://blog.meituo.net/wp-content/uploads/php_return_json/test.js', function(data) {
              $('#resText').empty();
   var html = '';
   $.each( data  , function(commentIndex, comment) {
    html += '<div class="comment"><h6>' + comment['username'] + ':</h6><p class="para">' + comment['content'] + '</p></div>';
   })
  $('#resText').html(html);
         })
    })
})

<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");

if (in_array("Glenn",$people))
  {
  echo "Match found";
  }
else
  {
  echo "Match not found";
  }
?>

1 $fruit["apple"] = "red"; 

2 $fruit["banana"] = "yellow"; 

3 $fruit["pear"] = "green"; 

4 if(array_key_exists("apple", $fruit)){ 

5     printf("apple's color is %s",$fruit["apple"]); 

6 }

$fruits["apple"] = "red";
$fruits["banana"] = "yellow";
$fruits["watermelon"]="green";
$founded = array_search("green", $fruits);
if($founded)
 printf("%s was founded on %s.",$founded, $fruits[$founded])

$fruits["apple"] = "red";
$fruits["banana"] = "yellow";
$fruits["watermelon"]="green";
$keys = array_keys($fruits);
print_r($keys);

$foo[1]['a']['xx'] = 'bar 1';
$foo[1]['b']['xx'] = 'bar 2';
$foo[2]['a']['bb'] = 'bar 3';
$foo[2]['a']['yy'] = 'bar 4';
$foo[3]['c']['dd'] = 'bar 3';
$foo[3]['f']['gg'] = 'bar 3';
$foo['info'][1] = 'bar 5';

$result = array_search_re('bar 3', $foo);

print_r($result);

输出结果为如下：
Array ( [0] => Array ( [1] => 2 [2] => a [3] => bb )
          [1] => Array ( [1] => 3 [2] => c [3] => dd )
          [2] => Array ( [1] => 3 [2] => f [3] => gg )
        )

function array_search_key($needle, $haystack){
global $nodes_found;

foreach ($haystack as $key1=>$value1) {
 
 if ($key1=== $needle){
 
  $nodes_found[] = $value1;
      
   }
    if (is_array($value1)){  
      array_search_key($needle, $value1);
    }
  
  
}

return $nodes_found;
}
$result = array_search_key('a', $foo);

print_r($result);

输出结果为如下：
 

Array
(
    [0] => Array
        (
            [xx] => bar 1
        )

    [1] => Array
        (
            [bb] => bar 3
        )

    [2] => Array
        (
            [yy] => bar 4
        )

)

<?php
 
//获取文件夹大小
function dir_size($dir) {
    if (!preg_match('#/$#', $dir)) {
        $dir .= '/';
    }
    $totalsize = 0;
    //调用文件列表
    foreach (get_file_list($dir) as $name) {
        $totalsize += (@is_dir($dir.$name) ? dir_size("$dir$name/") :
            (int)@filesize($dir.$name));
    }
    return $totalsize;
}
 
//获取文件列表
function get_file_list($path) {
    $f = $d = array();
    //获取所有文件
    foreach (get_all_files($path) as $name) {
        if (@is_dir($path.$name)) {
            $d[] = $name;
        } else if (@is_file($path.$name)) {
            $f[] = $name;
        }
    }
    natcasesort($d);
    natcasesort($f);
    return array_merge($d, $f);
}
 
//获取所有文件
function get_all_files($path) {
    $list = array();
    if (($hndl = @opendir($path)) === false) {
        return $list;
    }
    while (($file=readdir($hndl)) !== false) {
        if ($file != '.' && $file != '..') {
            $list[] = $file;
        }
    }
    closedir($hndl);
    return $list;
}
 
//转换单位
function setupSize($fileSize) {
    $size = sprintf("%u", $fileSize);
    if($size == 0) {
        return("0 Bytes");
    }
    $sizename = array(" Bytes", " KB", " MB", " GB", " TB", " PB", " EB", " ZB", " YB");
    return round($size/pow(1024, ($i = floor(log($size, 1024)))), 2) . $sizename[$i];
}
 
//目录
$path = './test_dir/';
 
//显示文件列表
print_r(get_file_list($path)).'<br>';
 
//显示文件大小
echo dir_size($path).'<br>';
 
//显示转换过单位的大小
echo setupSize(dir_size($path));
 
?>

<?php

function getDirSize($dir)
    {
        $handle = opendir($dir);
        while (false!==($FolderOrFile = readdir($handle)))
        {
            if($FolderOrFile != "." && $FolderOrFile != "..")
            {
                if(is_dir("$dir/$FolderOrFile"))
                {
                    $sizeResult += getDirSize("$dir/$FolderOrFile");
                }
                else
                {
                    $sizeResult += filesize("$dir/$FolderOrFile");
                }
            }   
        }
        closedir($handle);
        return $sizeResult;
    }

    // 单位自动转换函数
    function getRealSize($size)
    {
        $kb = 1024;         // Kilobyte
        $mb = 1024 * $kb;   // Megabyte
        $gb = 1024 * $mb;   // Gigabyte
        $tb = 1024 * $gb;   // Terabyte
       
        if($size < $kb)
        {
            return $size." B";
        }
        else if($size < $mb)
        {
            return round($size/$kb,2)." KB";
        }
        else if($size < $gb)
        {
            return round($size/$mb,2)." MB";
        }
        else if($size < $tb)
        {
            return round($size/$gb,2)." GB";
        }
        else
        {
            return round($size/$tb,2)." TB";
        }
    }

    echo getRealSize(getDirSize(dirname($_SERVER[SCRIPT_FILENAME])./include/));

?>

#########################################################

//function dirsize($dir)
//{
//   $handle=opendir($dir);
//   $size = 0;
//   while ( $file=readdir($handle) )
//   {
//       if ( ( $file == "." ) || ( $file == ".." ) ) continue;
//       if ( is_dir("$dir/$file") )
//           $size += dirsize("$dir/$file");
//       else
//           $size += filesize("$dir/$file");
//   }
//   closedir($handle);
//   return $size;
//}
//$big=dirsize(dirname($_SERVER[SCRIPT_FILENAME])."/");
//echo $big;