黄聪：php计算获取页面执行时间

//Create a variable for start time   
    $time_start = microtime(true);   
       
    // Place your PHP/HTML/JavaScript/CSS/Etc. Here   
       
    //Create a variable for end time   
    $time_end = microtime(true);   
    //Subtract the two times to get seconds   
    $time = $time_end - $time_start;   
       
    echo 'Script took '.$time.' seconds to execute';