php elseif 与else if区别

php elseif 与else if区别

if、elseif 以及 else 语句用于执行基于不同条件的不同动作。

条件语句
当您编写代码时，您常常需要为不同的判断执行不同的动作。
您可以在代码中使用条件语句来完成此任务。

if($condition1)  
  {  
  }  
  else    
  if($condition2)  
  {  
  }  
  else  
  {  
  }  
  //不能再有elseif().  
  和  
  if($condition1)  
  {  
  }  
  elseif($condition2)  
  {  
  }  
  else  
  {  
  }  
<?php
$d=date("D");
if ($d=="Fri")
  echo "Have a nice weekend!";
elseif ($d=="Sun")
  echo "Have a nice Sunday!";
else
  echo "Have a nice day!";
?>

if...else 语句
在条件成立时执行一块代码，条件不成立时执行另一块代码
elseif 语句
与 if...else 配合使用，在若干条件之一成立时执行一个代码块 If...Else 语句
如果您希望在某个条件成立时执行一些代码，在条件不成立时执行另一些代码，请使用 if....else 语句。
语法
if (condition)
  code to be executed if condition is true;
else
  code to be executed if condition is false;

php 经典分页 支持上10页下10代码
 +-------------------------------------------
 |
 |   Autohr : jimmy
 | Email : mailangel123@163.com
 |
 +-------------------------------------------
 */

 /*
 +-------------------------------------------
 + 配置不前页面
 +-------------------------------------------
 */
 if (@!$perpage || !is_numeric(@$perpage) || @$perpage <= 0){
  $perpage = 20;
 }
 /*
 +-------------------------------------------
 + 统计最大页面 tds记录总条数据
 +-------------------------------------------
 */
 $pages = ceil($tds / $perpage);
 /*
 +-------------------------------------------
 + 统计最大页面
 +-------------------------------------------
 */
 $page = $page > $pages ? $pages : $page;
 $page = is_numeric($page) && $page > 0 ? ceil($page/1) : 1;
 /*
 +-------------------------------------------
 + 取多少条记录
 +-------------------------------------------
 */
 $pages_limit = ($page - 1) * $perpage;
 $pages_offset = $perpage;
 /*
 +-------------------------------------------
 + 开始页与结束页面
 +-------------------------------------------
 */
 if ($pages <= 10){
  $spage = 1;
  $epage = $pages;
 }else{
  if ($page > $pages - 5){
   $spage = $pages - 9;
   $epage = $pages;
  }elseif ($page < 6){
   $spage = 1;
   $epage = 10;
  }else{
   $spage = $page - 4;
   $epage = $page + 5;
  }
 }
 /*
 +-------------------------------------------
 + 上一页与下一页
 +-------------------------------------------
 */
 $pages_prev = $page <= 2 ? 1 : ($page - 1);
 $pages_next = $page >= $pages-1 ? $pages : ($page + 1);

ajax+php检测文章标题是否存在代码
php代码
function checkTitle()
 {
  $title = PostGet('title');
  if( empty( $title ) )
  {
   return false;
  }
  else
  {
   $Db = new Db();
   $row = $Db->query("Select * from news where title ='$title'");
   if( $Db->rows( $row ) )
   {
    echo 1;
   }
   else
   {
    return NULL;
   }
  }
 }
js代码
function createXMLHttpRequest(){//创建XMLHttpRequest对象
 if(window.ActiveXObject){//IE
  try {
   return new ActiveXObject("Microsoft.XMLHTTP");
  } catch(e){
   return;
  }
 }else if(window.XMLHttpRequest){//Mozilla,firefox
  try {
   return new XMLHttpRequest();
  } catch(e){
   return;
  }
 }
}

function getreNews(Value){//主调函数
 var xmlHttp=createXMLHttpRequest();
 var url = "public.php?action=check&title="+Value+"&mt="+Math.random(300000);
 if (Value==""){  
  return false ;
 }
 if (xmlHttp){
  callback = getReadyStateHandler(xmlHttp);
  xmlHttp.onreadystatechange = callback;
  xmlHttp.open("GET", url,true);
  xmlHttp.send(null);
 }
}

function getReadyStateHandler(xmlHttp){//服务器返回后处理函数
 return function (){
  if(xmlHttp.readyState == 4){
   if(xmlHttp.status == 200){
       
     if (xmlHttp.responseText==1){
       document.getElementById("checkid").innerHTML="<font color='red'><img src=../img/e.gif />对不起，你输入的标题存在重复哦！</font>";     
     }else{
      document.getElementById("checkid").innerHTML="<img src=../img/g.gif />";     
     }      
   }
  }
 }
}

html代码

<input name="title" type="text" id="title" size="60" onblur="getreNews(this.value);" />
<span id="checkid"></span>

这一句了，简单吧。

php image_type_to_mime_type

image_type_to_mime_type - 获取MIME的图像类型和getimagesize返回类型，exif_read_data，exif_thumbnail，本函数

<?php
$filename = 'http://111cn.net/banner/banner.gif';
$size = getimagesize($filename);

switch ($size['mime']) {
    case "image/gif":
        echo "Image is a gif";
        break;
    case "image/jpeg":
        echo "Image is a jpeg";
        break;
    case "image/png":
        echo "Image is a png";
        break;
    case "image/bmp":
        echo "Image is a bmp";
        break;
}
?>

<?php
print image_type_to_mime_type(IMAGETYPE_ICO);
// returns: application/octet-stream
?>

php Curl保存远程服务器图片

function LoadImageCURL($save_to){
        $ch = curl_init($this->source);
        $fp = fopen($save_to, "wb");
       
        // set URL and other appropriate options
        $options = array(CURLOPT_FILE => $fp,
                         CURLOPT_HEADER => 0,
                         CURLOPT_FOLLOWLOCATION => 1,
                         CURLOPT_TIMEOUT => 60); // 1 minute timeout (should be enough)
       
        curl_setopt_array($ch, $options);
       
        curl_exec($ch);
        curl_close($ch);
        fclose($fp);

    }

$info = @GetImageSize($this->source);
    $mime = $info['mime'];
   
// What sort of image?
    $type = substr(strrchr($mime, '/'), 1);
    switch ($type){
        case 'jpeg':
            $image_create_func = 'ImageCreateFromJPEG';
            $image_save_func = 'ImageJPEG';
            $new_image_ext = 'jpg';
       
            // Best Quality: 100
            $quality = isSet($this->quality) ? $this->quality : 100;
            break;
       
        case 'png':
            $image_create_func = 'ImageCreateFromPNG';
            $image_save_func = 'ImagePNG';
            $new_image_ext = 'png';
       
            // Compression Level: from 0  (no compression) to 9
            $quality = isSet($this->quality) ? $this->quality : 0;
            break;
       
        case 'bmp':
            $image_create_func = 'ImageCreateFromBMP';
            $image_save_func = 'ImageBMP';
            $new_image_ext = 'bmp';
            break;
       
        case 'gif':
            $image_create_func = 'ImageCreateFromGIF';
            $image_save_func = 'ImageGIF';
            $new_image_ext = 'gif';

            break;
       
        case 'vnd.wap.wbmp':
            $image_create_func = 'ImageCreateFromWBMP';
            $image_save_func = 'ImageWBMP';
            $new_image_ext = 'bmp';
            break;
       
        case 'xbm':
            $image_create_func = 'ImageCreateFromXBM';
            $image_save_func = 'ImageXBM';
            $new_image_ext = 'xbm';
            break;
       
        default:
            $image_create_func = 'ImageCreateFromJPEG';
            $image_save_func = 'ImageJPEG';
            $new_image_ext = 'jpg';
    }
   
    if(isSet($this->set_extension)){
        $ext = strrchr($this->source, ".");
        $strlen = strlen($ext);
        $new_name = basename(substr($this->source, 0, -$strlen)).'.'.$new_image_ext;
    }else{
        $new_name = basename($this->source);
    }
   
    $save_to = $this->save_to."/blog_insert_temp_".time().mt_rand(1,99).".".$new_image_ext;
    //输出对象 组成跟$_FILE变量一样 得到后自己和平常图片上传处理一样了
    $img_info['name'] = basename($this->source);
    $img_info['type'] = $mime;
    $img_info['size'] = 1000;
    $img_info['tmp_name'] = $save_to;
    $img_info['error'] = 0;
       
    if($method == 'curl'){
        $save_image = $this->LoadImageCURL($save_to);
    }elseif($method == 'gd'){
        $img = $image_create_func($this->source);
   
            if(isSet($quality)){
               $save_image = $image_save_func($img, $save_to, $quality);
            }else{
               $save_image = $image_save_func($img, $save_to);
            }
          
    }
         return $img_info;
    }