我正在从内部存储中检索一些数据,如果出现故障,我会得到非常具体的响应。对此变量调用strlen()
将返回零值。它也不等于NULL或"。我用这个代码来测试:
if ($data === NULL)
{
echo("data was null'n");
}
else if ($data === "")
{
echo("data was empty string'n");
}
else if (strlen($data) == 0)
{
echo("data was length zero'n");
}
该结果是输出CCD_ 2。变量可以包含零长度、非null和非空字符串的内容?
则返回值必须为false。
echo strlen(false); // outputs 0
这可能不是一个答案。我只能在你出示var_dump($data);
的情况下回答,但我想让我惊讶的是:
$data = "'0";
if ($data === NULL)
{
echo("data was null'n");
}
else if ($data === "")
{
echo "data was empty string'n";
}
else if (strlen($data) == 0)
{
echo "data was length zero'n";
}
else
{
echo "something strange happened'n";
}
输出:something strange happened
:)
试试这个:
$data = false;
我不知道为什么false有strlen,但它有。