php 将空值转换为字符串
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Convert null to string
提问by laukok
Is it possible to convert nullto stringwith php?
是否有可能转换null到string用PHP？
For instance,
例如，
$string = null;
to
到
$string = "null";
回答by dev-null-dweller
var_exportcan represent any variable in parseable string.
var_export可以表示可解析字符串中的任何变量。
回答by Matt Ball
Am I missing something here?
我在这里错过了什么吗？
if ($string === null) {
$string = 'null';
}
was thinking something shorter...
在想更短的东西......
You can do it in one line, and omitthe braces:
if ($string === null) $string = 'null';
You can also use the conditional operator:
您还可以使用条件运算符：
$string = ($string === null) ? 'null' : $string;
Your call.
您的来电。
回答by Omar
in PHP 7 you can use Null coalescing operator ??
在 PHP 7 中，您可以使用 Null 合并运算符 ??
$string = $string ?? 'null';
回答by dvvrt
While not very elegant or legible, you can also do the following
虽然不是很优雅或清晰，但您也可以执行以下操作
is_null($string) && $string = 'null'; // assignment, not a '==' comparison
// $string is 'null'
or
或者
$string = is_null($string) ? gettype($string) : $string;
// $string is 'NULL'
Note: var_export($string, true)(mentioned in other replies) returns 'NULL'
注：（var_export($string, true)在其他回复中提到）退货'NULL'
回答by Oleksi
if ($string === null)
{
$string = "null";
}
回答by user1303559
it has best solution:
它有最好的解决方案：
$var = null;
$stringNull = json_encode($var);
$null = json_decode($stringNull, true);
var_dump($stringNull);
var_dump($null);
