php数组删除元素各种方法总结

<?php
$a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird");
print_r(array_slice($a,1,2));
?>

输出

Array ( [0] => Cat [1] => Horse )

$array = array('1', '2', '3', '4', '5');

$del_value = 3;
unset($array[array_search($del_value , $array)]);//利用unset删除这个元素

print_r($array);

输出

array('1', '2', '4', '5');

$fruits = array("apple","banana","orange","pear");
$fruit = array_shift($fruits);
// $fruits = array("banana","orange","pear")
// $fruit = "apple";

$fruits = array("apple","banana","orange","pear");
$fruit = array_pop($fruits);
//$fruits = array("apple","banana","orange");
//$fruit = "pear";

function deleteElementFromArr($arr, $index){
if($index < count($arr)-1){
unset($arr[$index]);
reset($arr);
}
return $arr;
}

<?php

function array_remove(&$arr, $offset)
{
array_splice($arr, $offset, 1);
}

$arr = array('apple','banana','cat','dog');

array_remove($arr, 2);
print_r($arr);
?>

<?php
function assoc_unique($arr, $key) {
$tmp_arr = array();
foreach($arr as $k => $v) {
if(in_array($v[$key], $tmp_arr)) {
unset($arr[$k]);
} else {
$tmp_arr[] = $v[$key];
}
}
sort($arr);
return $arr;
}

$aa = array(
array('id' => 123, 'name' => '张三'),
array('id' => 123, 'name' => '李四'),
array('id' => 124, 'name' => '王五'),
array('id' => 125, 'name' => '赵六'),
array('id' => 126, 'name' => '赵六')
);
$key = 'name';
assoc_unique(&$aa, $key);
print_r($aa);
?>

max_execution_time = 30     ; Maximum execution time of each script, in seconds
max_input_time = 60    ; Maximum amount of time each script may spend parsing request data
;max_input_nesting_level = 64 ; Maximum input variable nesting level
memory_limit = 128M      ; Maximum amount of memory a script may consume (128MB)

; Maximum size of POST data that PHP will accept.
post_max_size = 105M

; Maximum allowed size for uploaded files.
upload_max_filesize = 100M

set_time_limit(0);

 <form action="<?php echo @htmlspecialchars($url['login_url']) ?>"  method="post" enctype="application/x-www-form-urlencoded" name="form1" id="form1">
        <p><label>工资号：</label>
            <input name="Login.Token1" class="text" type="text" id="token1" />
        </p>
        <p><label>密 码：</label>
            <input name="Login.Token2" class="text" type="password" id="token2" />
        </p>
        <p>
            <input name="登录" type="submit" id="user_login" value="登录" />
            <input type="reset" value="重置" />
        </p>
        <b style="color:red"><?php echo $this->session->flashdata('error'); ?></b>
    </form>
<script>
    $(function(){
        $("#user_login").click(function(){
            var username = $("#token1").val();
            var salary_no = $("#token2").val();
            $.ajax({
                type: "POST",
                data: "username="+username+"&salary_no="+salary_no,
                url: "<?php echo site_url('home/ajax_check_username')?>",
                dataType: "text",
                cache: false,
                error: function(){alert('error');},
                success: function(data){
                    if(data == 'yes'){
                        location.href="<?php echo site_url('home/index')?>";
                    }else{
                        form1.submit();
                    }
                }
            });
            return false;
        });
    });
</script>

    #提交到本地
    function ajax_check_username(){
        //redirect('home/index');
        $username = $this->input->post("username");
        $salary_no = $this->input->post("salary_no");
        if($this->user_mdl->check_ajax_user($username,$salary_no)){
            $this->session->set_userdata('salary_no', $salary_no);
            $this->session->set_userdata('username', $username);
            echo "yes";
        }else{
            echo "no";
        }
    }

<div class="demo"> 
      <div id="total">当前在线：<span id="onlinenum"></span></div> 
    <ul id="onlinelist"> 
        <li><img src="loader.gif"></li> 
    </ul> 
</div> 

CREATE TABLE IF NOT EXISTS `online` ( 
  `id` int(11) NOT NULL AUTO_INCREMENT, 
  `ip` varchar(30) NOT NULL, 
  `province` varchar(64) NOT NULL, 
  `addtime` int(10) NOT NULL DEFAULT '0', 
  PRIMARY KEY (`id`) 
) ENGINE=MyISAM  DEFAULT CHARSET=utf8; 

include_once('connect.php'); //连接数据库 
 
$ip = get_client_ip(); //获取客户端IP 
$time = time(); 
//查询表中是否有ip为当前访客IP的记录 
$query = mysql_query("select id from online where ip='$ip'"); 
if(!mysql_num_rows($query)){//如果不存在访客IP 
    if($_COOKIE['geoData']){//如果存在cookie，则获取用户的区域 
        $province = $_COOKIE['geoData']; //区域（省份） 
    }else{ 
        $api = "http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=json&ip=$ip"; 
        $json = file_get_contents($api);//调用新浪IP地址库 
        $arr = json_decode($json,true);//解析json 
        $province = $arr['province'];//获取省份 
        setcookie('geoData',$province,$time+600); //设置cookie，设置过期时间为10分钟 
    } 
    //将访客信息插入到数据表中 
    mysql_query("insert into online (ip,province,addtime) values ('$ip','$province','$time')"); 
}else{//如果存在，则更新该用户访问时间 
    mysql_query("update online set addtime='$time' where ip='$ip'"); 
} 
//删除已过期的记录 
$outtime = $time-600; 
mysql_query("delete from online where addtime<$outtime"); 
//统计总记录数，即在线用户数 
list($totalOnline) = mysql_fetch_array(mysql_query("select count(*) from online"));  
echo $totalOnline;//输出在线总数 
mysql_close(); 

function get_client_ip() { 
    if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown")) 
        $ip = getenv("HTTP_CLIENT_IP"); 
    else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"),  
"unknown")) 
        $ip = getenv("HTTP_X_FORWARDED_FOR"); 
    else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown")) 
        $ip = getenv("REMOTE_ADDR"); 
    else if (isset ($_SERVER['REMOTE_ADDR']) &&  
$_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown")) 
        $ip = $_SERVER['REMOTE_ADDR']; 
    else 
        $ip = "unknown"; 
    return ($ip); 
} 

include_once('connect.php');//连接数据库 
//查询区域统计 
$sql = "select province,count(*) as total from online group by province order by total desc"; 
$result = mysql_query($sql); 
while($row=mysql_fetch_array($result)){ 
    $list[] = array( 
        'province' => $row['province'], 
        'total' => $row['total'] 
    );     
} 
echo json_encode($list);//以json格式输出 

$(function(){ 
    $("#onlinenum").load("online.php"); 
     
    $(".demo").hover(function(){ 
        $("#onlinelist").slideDown("fast"); 
        var str = ''; 
        $.getJSON("geo.php",function(json){ 
            $.each(json,function(index,array){ 
                str = str + "<li><span>"+array['total']+"</span>"+array['province']+"</li>"; 
            }); 
            $("#onlinelist").html(str); 
        }); 
    },function(){ 
        $("#onlinelist").slideUp("fast"); 
    }); 
}); 

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>PHP+MySQL+jQuery统计当前在线用户数</title>
<link rel="stylesheet" type="text/css" href="../css/main.css" />
<style type="text/css">
.demo{width:150px; margin:20px auto; font-size:14px; position:relative}
#total{padding:6px 10px; background:#090 url(arr.png) no-repeat right top; color:#fff; cursor:pointer; -moz-border-radius:5px; -webkit-border-radius:5px; border-radius:5px; -moz-box-shadow:0 0 3px #ccc; -webkit-box-shadow:0 0 3px #ccc;box-shadow:0 0 3px #ccc;}
#onlinelist{background:#f7f7f7; border:1px solid #d3d3d3; display:none; -moz-border-radius:5px; -webkit-border-radius:5px; border-radius:5px; -moz-box-shadow:0 0 3px #ccc; -webkit-box-shadow:0 0 3px #ccc;box-shadow:0 0 3px #ccc; position:absolute; top:30px; width:150px}
#onlinelist li{height:20px; line-height:20px; padding:4px 6px; border-bottom:1px dotted #d9d9d9}
#onlinelist li span{float:right}
#onlinelist li:hover{background:#fff}
</style>
<script type="text/javascript" src="../js/jquery.js"></script>
<script type="text/javascript">
$(function(){
 $("#onlinenum").load("online.php");
 
 $(".demo").hover(function(){
  $("#onlinelist").slideDown("fast");
  var str = '';
  $.getJSON("geo.php",function(json){
   $.each(json,function(index,array){
    str = str + "<li><span>"+array['total']+"</span>"+array['province']+"</li>";
   });
   $("#onlinelist").html(str);
  });
 },function(){
  $("#onlinelist").slideUp("fast");
 });
});
</script>
</head>

<body>

<div id="main">
  <h2 class="top_title"><a href="blog-206.html" title="点击看教程">PHP+MySQL+jQuery统计当前在线用户数</a></h2>
  <div class="demo">
   <div id="total">当前在线：<span id="onlinenum"></span></div>
    <ul id="onlinelist">
     <li><img src="loader.gif"></li>
    </ul>
  </div>
  <br/><br/><br/><br/><br/>
 
</div>

</body>
</html>

CREATE TABLE IF NOT EXISTS `downloads` ( 
  `id` int(6) unsigned NOT NULL AUTO_INCREMENT, 
  `filename` varchar(50) NOT NULL, 
  `savename` varchar(50) NOT NULL, 
  `downloads` int(10) unsigned NOT NULL DEFAULT '1', 
  PRIMARY KEY (`id`), 
  UNIQUE KEY `filename` (`filename`) 
) ENGINE=MyISAM  DEFAULT CHARSET=utf8; 

<div id="demo"> 
    <ul class="filelist"> 
    </ul> 
</div> 

#demo{width:728px;margin:50px auto;padding:10px;border:1px solid #ddd;background-color:#eee;} 
ul.filelist li{background:url("img/bg_gradient.gif") repeat-x center bottom #F5F5F5; 
border:1px solid #ddd;border-top-color:#fff;list-style:none;position:relative;} 
ul.filelist li.load{background:url("img/ajax_load.gif") no-repeat; padding-left:20px;  
border:none; position:relative; left:150px; top:30px; width:200px} 
ul.filelist li a{display:block;padding:8px;} 
ul.filelist li a:hover .download{display:block;} 
span.download{background-color:#64b126;border:1px solid #4e9416;color:white; 
display:none;font-size:12px;padding:2px 4px;position:absolute;right:8px; 
text-decoration:none;text-shadow:0 0 1px #315d0d;top:6px; 
-moz-border-radius:3px;-webkit-border-radius:3px;border-radius:3px;} 
span.downcount{color:#999;padding:5px;position:absolute; margin-left:10px;text-decoration:none;} 

require 'conn.php'; //连接数据库 
$result = mysql_query("SELECT * FROM downloads"); 
if(mysql_num_rows($result)){ 
    while($row=mysql_fetch_assoc($result)){ 
        $data[] = array( 
            'id' => $row['id'], 
            'file' => $row['filename'], 
            'downloads'=> $row['downloads'] 
        ); 
    } 
    echo json_encode($data); 
} 

require('conn.php');//连接数据库 
$id = (int)$_GET['id']; 
 
if(!isset($id) || $id==0) die('参数错误!'); 
$query = mysql_query("select * from downloads where id='$id'"); 
$row = mysql_fetch_array($query); 
if(!$row) exit; 
$filename = iconv('UTF-8','GBK',$row['filename']);//中文名称注意转换编码 
$savename = $row['savename']; //实际在服务器上的保存名称 
$myfile = 'file/'.$savename; 
if(file_exists($myfile)){//如果文件存在 
    //更新下载次数 
    mysql_query("update downloads set downloads=downloads+1 where id='$id'"); 
    //下载文件 
    header("Content-type: application/octet-stream"); 
    header("Content-Disposition: attachment; filename=" .$filename ); 
    exit; 
}else{ 
    echo '文件不存在！'; 
} 

$(function(){ 
    $.ajax({ //异步请求 
        type: 'GET', 
        url: 'filelist.php', 
        dataType: 'json', 
        cache: false, 
        beforeSend: function(){ 
            $(".filelist").html("<li class='load'>正在载入...</li>"); 
        }, 
        success: function(json){ 
            if(json){ 
                var li = ''; 
                $.each(json,function(index,array){ 
                    li = li + '<li><a href="download.php?id='+array['id']+'">'+array['file']+ 
'<span class="downcount" title="下载次数">'+array['downloads']+'</span> 
<span class="download">点击下载</span></a></li>'; 
                }); 
                $(".filelist").html(li); 
            } 
        } 
    }); 
    $('ul.filelist a').live('click',function(){ 
        var count = $('.downcount',this); 
        count.text( parseInt(count.text())+1); //下载次数+1 
    }); 
});