php：如何删除起始空格和新行

Question

我有一个字符串，

"

     it is a dog"

如何删除起始空白和新行？ 输出应为：

"it is a dog"

我尝试了preg_replace("/^\s*/ms", "", $string)，但没有效果。

Answer 1

尝试ltrim (http://php.net/ltrim）。

Answer 2

使用trim。

来自php.net的

示例：

$text   = "\t\tThese are a few words :) ...  ";
$binary = "\x09Example string\x0A";
$hello  = "Hello World";
var_dump($text, $binary, $hello);

print "\n";

$trimmed = trim($text);
var_dump($trimmed);

$trimmed = trim($text, " \t.");
var_dump($trimmed);

$trimmed = trim($hello, "Hdle");
var_dump($trimmed);

$trimmed = trim($hello, 'HdWr');
var_dump($trimmed);

// trim the ASCII control characters at the beginning and end of $binary
// (from 0 to 31 inclusive)
$clean = trim($binary, "\x00..\x1F");
var_dump($clean);

以上示例将输出：

string(32) "        These are a few words :) ...  "
string(16) "    Example string
"
string(11) "Hello World"

string(28) "These are a few words :) ..."
string(24) "These are a few words :)"
string(5) "o Wor"
string(9) "ello Worl"
string(14) "Example string"

Answer 3

你可以试试这个：

$string = str_replace(array("\r", "\n"), '', trim($string));