7個超級實用的PHP程式碼片段分享(1)_PHP教程

1、超級簡單的頁面緩衝

如果你的工程項目不是基於 CMS 系統或架構，打造一個簡單的緩衝系統將會非常實在。下面的代碼很簡單，但是對小網站而言能切切實實解決問題。

 

  

  
 // define the path and name of cached file  
  
 $cachefile = 'cached-files/'.date('M-d-Y').'.php'; 
  
 // define how long we want to keep the file in seconds. I set mine to 5 hours.  
  
 $cachetime = 18000; 
  
 // Check if the cached file is still fresh. If it is, serve it up and exit.  
  
 if (file_exists($cachefile) && time() - $cachetime < filemtime($cachefile)) { 
  
 include($cachefile); 
  
 exit; 
  
 } 
  
 // if there is either no file OR the file to too old, render the page and capture the HTML.  
  
 ob_start(); 
  
?> 
  
  
  
 output all your html here. 
  
  
  

  
 // We're done! Save the cached content to a file  
  
 $fp = fopen($cachefile, 'w'); 
  
 fwrite($fp, ob_get_contents()); 
  
 fclose($fp); 
  
 // finally send browser output  
  
 ob_end_flush(); 
  
?> 
 

點擊這裡查看詳細情況：http://wesbos.com/simple-php-page-caching-technique/

2、在 PHP 中計算距離

這是一個非常有用的距離計算函數，利用緯度和經度計算從 A 地點到 B 地點的距離。該函數可以返回英裡，公裡，海裡三種單位類型的距離。

 

  
function distance($lat1, $lon1, $lat2, $lon2, $unit) { 
  
 
  
 $theta = $lon1 - $lon2; 
  
 $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta)); 
  
 $dist = acos($dist); 
  
 $dist = rad2deg($dist); 
  
 $miles = $dist * 60 * 1.1515; 
  
 $unit = strtoupper($unit); 
  
 
  
 if ($unit == "K") { 
  
 return ($miles * 1.609344); 
  
 } else if ($unit == "N") { 
  
 return ($miles * 0.8684); 
  
 } else { 
  
 return $miles; 
  
 } 
  
} 
 

使用方法：

 

  
echo distance(32.9697, -96.80322, 29.46786, -98.53506, "k")." kilometers"; 
 

點擊這裡查看詳細情況：http://www.phpsnippets.info/calculate-distances-in-php

3、將秒數轉換為時間(年、月、日、小時…)

這個有用的函數能將秒數表示的事件轉換為年、月、日、小時等時間格式。

 

  
function Sec2Time($time){ 
  
 if(is_numeric($time)){ 
  
 $value = array( 
  
 "years" => 0, "days" => 0, "hours" => 0, 
  
 "minutes" => 0, "seconds" => 0, 
  
 ); 
  
 if($time >= 31556926){ 
  
 $value["years"] = floor($time/31556926); 
  
 $time = ($time%31556926); 
  
 } 
  
 if($time >= 86400){ 
  
 $value["days"] = floor($time/86400); 
  
 $time = ($time%86400); 
  
 } 
  
 if($time >= 3600){ 
  
 $value["hours"] = floor($time/3600); 
  
 $time = ($time%3600); 
  
 } 
  
 if($time >= 60){ 
  
 $value["minutes"] = floor($time/60); 
  
 $time = ($time%60); 
  
 } 
  
 $value["seconds"] = floor($time); 
  
 return (array) $value; 
  
 }else{ 
  
 return (bool) FALSE; 
  
 } 
  
} 
 

點擊這裡查看詳細情況：http://ckorp.net/sec2time.php

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