public static MyClass {
    private static volatile ProcessManager singleton = null;
    
    public static ProcessManager getInstance() throws Exception {
        if (singleton == null) {
            synchronized (MyClass.class) {
                if (singleton == null) {
                    singleton = new ProcessManager();
                }
            }
        }
        return singleton;
    }
}

The double-checking was invented prior to Java5.

The purpose is if the field isn't null, you don't have to synchronize. But since the java memory model specification was cleaned up and Synchronize/Volatile were given much better specification and semantics it is totally useless boilerplate that you should only write if you have to support Java4. There is a Google Tech Talk that covers this.

By cody, 2017-12-12 08:02:01
foreach($bookings as $booking) {
	$status = $apiController->getBookingStatus($booking);
	if($status->error == 1) {
		switch($status->message) {
			case "FIND_PRV_KO": continue; //Wrong parameters
			case "ERR_PREN_NOTFOUND": continue; //Request booking cannot be found
			case "ERR_PRV_NOTFOUND": continue; //Check-in not carried out
			default: continue;
		};
		continue;
	}
	//DO SOME STUFF...
}

Found this on a production website

By Samuel, 2021-03-29 17:52:33
$MaxSizeGB = [math]::Round($MaxSize/1024/1024/1024,2)
Write-Output "    the maximum size is $MaxSizeGB GB"

At least [math] is used. So close, and yet so far...

By Anonymous, 2020-04-03 20:59:34
var div = '<div class="imgdiv" '+(user[5] ? 'style="display: flex; flex-direction: column; padding: 10px; justify-content: flex-end; background-image: url(\''+user[5]+'\');"' : '')+'>'
        + (usersVideos[userId] && <?= ($authuser ? 'true' : 'false') ?> ? '<i class="f7-icons icon-acc" onclick="videoShow('+user[uID]+')" style="color: white; font-size: 50px; margin-bottom: 5px; cursor: pointer; text-align: left;">play_round</i>' : '')
        + (iam && page=='home' ? '<div> <input id="video-input" onchange="uploadVideo(files)" type="file" accept="video/*" style="display: none; width: 80%; height: 100px; margin: auto; padding-top: 20px;"/> </div> <p class="action_cont" style="padding: 0; padding-top: 12;"> <a class="act_btn" onmousedown=document.getElementById("video-input").click() href="javascript:void(0)" style="text-decoration: none; margin: auto; width: calc(100% - 26px); text-align: center;"> ' + (myMods['video'] ? 'Загрузить новое видео' : 'Добавить видео-превью' ) + ' </a> </p>' : '')
+ '</div>'

JS + CSS + PHP + HTML

By Anon, 2018-08-24 18:30:12
# Weird list cleanup
product = "{0}".format(list(product))
product = re.sub(r"\), \(+", "], [", product)
product = re.sub(r"\(+", "[", product)
product = product.replace(")]", "]]").replace(")", "")
product = ast.literal_eval(product)

I don't know why I get this strange fomat for this array of objects... Ok let's do it fast: 1 - Convert array in string 2 - Clean up string 3 - Convert string in array

By Anonymous, 2018-09-05 23:51:16
bool calculateLeapYear(uint8_t year) {
    if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)) {
        return true;
    } else {
        return false;
    }
}

uint8_t and a useless if.

By eha, 2023-06-19 23:01:57
 if (!String.IsNullOrEmpty(Client.CLADDR1))
            {
                if (Client.CLADDR1 == "NULL")
                {
By Anonymous, 2017-06-29 12:33:24
<?php
    if(isset($_POST['csrf'])){
        if($_POST['csrf'] !== $_SESSION['csrf']){
            return 'session expired!';
        }
    }

In all Sama Samaneh university and class management system from iran :)

By Mahmoud etc, 2017-12-14 11:21:23
// IsFooBar being a boolean, we check if it's different from true and from false
if (x.IsFooBar != true && x.IsFooBar != false)
{
    return "error";
}

x.IsFooBar is juste a regular bool

By A senior developer, 2018-05-14 14:46:14
div.body:first-child:nth-last-child(n+12),
div.body:first-child:nth-last-child(n+12) ~ div.body {
  padding: 3px 5px 2px !important;

  div.rect {
    top: 6px !important;
  }

  div.legend-action {
    top: 3px !important;
  }
}
By Anonymous, 2018-06-04 10:46:38
/**
 * Stringify a JSON object
 * @param {*} value JSON value to stringify
 * @returns {string} stringify JSON
 */
function stringify(value) {
    var result = {};
    try {
        result = JSON.stringify(value);
    } catch (e) {
        Logger.error('Error while trying to stringify ' + e);
        result = JSON.stringify(result);
    }
    return result;
}

Stringify a JSON object

By Ihor Did, 2023-04-12 19:36:08
return [word for word in words if any(all(ch in row for ch in word.lower()) for row in rows)]

Filtering words that can be typed using only one row of the keyboard.

By Mark, 2019-02-27 15:53:46
maybeSomething match {
  case Some(x) => true
  case None => false
}

maybeSomething.getOrElse(false) Short code and readable

By Majid Hosseini, 2017-12-16 07:03:07
<?php 
$k =1;
for($v = 0; $v < $nt; $v++) {         
	$bgClass= 'blueBg';
		if($k > 1 && $k%2 == 0){
			$bgClass= 'whiteBg';
		}
?> 
<tr  class="row_tr <?php echo $bgClass;?>">						
			<td class="row_td td_column_0">&nbsp;</td>					
			<td class="row_td column_1"><?php echo $rows[$v]['nothing'];?></td>
			...
			<td class="row_td td_column_0">&nbsp;</td>
	</tr>

<?php       
	$k++;
	}	
?>
By Unknown, 2018-02-13 14:47:19
let length str =
    let len = String.length str in
    
    let rec length_helper str curr = 
    if str = "" then 0 else 1 + length_helper (String.sub str 1 (len - curr - 1)) (curr + 1)
    
    in length_helper str 0;;

We use this code internally at Google. JFC.

By Mark, 2018-04-21 21:51:57