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7个超级实用的PHP代码片段分享(1)_PHP教程

程序员文章站 2022-05-25 15:19:14
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1、超级简单的页面缓存

如果你的工程项目不是基于 CMS 系统或框架,打造一个简单的缓存系统将会非常实在。下面的代码很简单,但是对小网站而言能切切实实解决问题。

  1. // define the path and name of cached file
  2. $cachefile = 'cached-files/'.date('M-d-Y').'.php';
  3. // define how long we want to keep the file in seconds. I set mine to 5 hours.
  4. $cachetime = 18000;
  5. // Check if the cached file is still fresh. If it is, serve it up and exit.
  6. if (file_exists($cachefile) && time() - $cachetime filemtime($cachefile)) {
  7. include($cachefile);
  8. exit;
  9. }
  10. // if there is either no file OR the file to too old, render the page and capture the HTML.
  11. ob_start();
  12. ?>
  13. output all your html here.
  14. // We're done! Save the cached content to a file
  15. $fp = fopen($cachefile, 'w');
  16. fwrite($fp, ob_get_contents());
  17. fclose($fp);
  18. // finally send browser output
  19. ob_end_flush();
  20. ?>

点击这里查看详细情况:http://wesbos.com/simple-php-page-caching-technique/

2、在 PHP 中计算距离

这是一个非常有用的距离计算函数,利用纬度和经度计算从 A 地点到 B 地点的距离。该函数可以返回英里,公里,海里三种单位类型的距离。

  1. function distance($lat1, $lon1, $lat2, $lon2, $unit) {
  2. $theta = $lon1 - $lon2;
  3. $dist = sin(deg2rad($lat1)) * sin(deg2rad($lat2)) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * cos(deg2rad($theta));
  4. $dist = acos($dist);
  5. $dist = rad2deg($dist);
  6. $miles = $dist * 60 * 1.1515;
  7. $unit = strtoupper($unit);
  8. if ($unit == "K") {
  9. return ($miles * 1.609344);
  10. } else if ($unit == "N") {
  11. return ($miles * 0.8684);
  12. } else {
  13. return $miles;
  14. }
  15. }

使用方法:

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

点击这里查看详细情况:http://www.phpsnippets.info/calculate-distances-in-php

3、将秒数转换为时间(年、月、日、小时…)

这个有用的函数能将秒数表示的事件转换为年、月、日、小时等时间格式。

  1. function Sec2Time($time){
  2. if(is_numeric($time)){
  3. $value = array(
  4. "years" => 0, "days" => 0, "hours" => 0,
  5. "minutes" => 0, "seconds" => 0,
  6. );
  7. if($time >= 31556926){
  8. $value["years"] = floor($time/31556926);
  9. $time = ($time%31556926);
  10. }
  11. if($time >= 86400){
  12. $value["days"] = floor($time/86400);
  13. $time = ($time%86400);
  14. }
  15. if($time >= 3600){
  16. $value["hours"] = floor($time/3600);
  17. $time = ($time%3600);
  18. }
  19. if($time >= 60){
  20. $value["minutes"] = floor($time/60);
  21. $time = ($time%60);
  22. }
  23. $value["seconds"] = floor($time);
  24. return (array) $value;
  25. }else{
  26. return (bool) FALSE;
  27. }
  28. }

点击这里查看详细情况:http://ckorp.net/sec2time.php

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www.bkjia.comtruehttp://www.bkjia.com/PHPjc/445736.htmlTechArticle1、超级简单的页面缓存 如果你的工程项目不是基于 CMS 系统或框架,打造一个简单的缓存系统将会非常实在。下面的代码很简单,但是对小...