Question

用户可以输入：

<textarea name="sometext"></textarea>

我想只存储最多两个换行符。例如：

纠正1（简单换行符）：

This should be stored
This should be stored

纠正2：

This should be stored too

This should be stored too

错：

This should NOT be stored


This should NOT be stored

如果错误，应自动转换为示例2。

Answer 1

如果您只想计算换行符，可以使用substr_count()：

if (substr_count($input, "\n") > 2) {
    echo 'Invalid input';
}

Answer 2

似乎你想要避免多于一个空白行，在这种情况下，以下内容就足够了。

 $l1 = "This should be stored
 This should be stored";

 $l2 = "This should be stored too

 This should be stored too";

 $l3 = "This should NOT be stored


 This should NOT be stored";

 $expected_l3 = "This should NOT be stored

 This should NOT be stored";


 $examples = array($l1, $l2, $l3);
 $results = array();

 foreach ($examples as $example) {
   $lines = explode("\n", $example);
   $result = array();
   $blankLine = False;
   foreach ($lines as $ii => $line) {
     $line = trim($line);

     if ($blankLine and !$line) {
       continue;
     }
     $blankLine = False;

     $result[] = $line;

     if (!$line) {
       $blankLine = True;
     } 
   }

   $results[] = implode("\n", $result);
 }

 assert($results[0] == $l1);
 assert($results[1] == $l2);
 assert($results[2] == $expected_l3);

Answer 3

你说你想为每个字符串存储最多2个新行。所以我们需要将此字符串除以\n次出现次数。

$data = "This should be stored too\nThis should be stored too";

$lines = preg_split("/\n/", $data);

var_dump($lines);


$data2 = "This should NOT be stored\n\n\nThis should NOT be stored";


$lines = preg_split("/\n/", $data2);

var_dump($lines);

$newlines = 0;
for($i = 0; $i < count($lines); $i++) {
    if($lines[$i] == '') {
        $newlines++;
    }
}

if($newlines > 2) {
    // do the conersion here.
}

Answer 4

我认为@Anonymous几乎拥有它。如果我明白你在寻找什么，它似乎应该像下面这样。

if(substr_count($input,"\n\n\n")>0){
     $input=str_replace("\n\n\n","\n\n",$input); 
}

这将查找两个换行符，如果发现它们将删除它们。

PHP，SQL：仅存储来自用户输入的两个换行符

4 个答案: