我如何判断文件名是否包含两个或更多点

Question

我正在寻找如何判断文件名是否包含两个或更多点的方法。例如。45FGG.TESTDOC.MAY12.png, carimage.30.jpg。那么，如何用它的扩展名存储这个图像呢？

Answer 1

您可以使用正则表达式轻松计算点数：

PHP

preg_match_all("/\./", "45FGG.TESTDOC.MAY12.png"); // 3

JS

"45FGG.TESTDOC.MAY12.png".match(/\./g).length; // 3

Answer 2

下面是两个测试用例：

$file1 = "hello.jpg";

$file2 = "hello.file.jpg";

echo "\$file1: " . $file1 . "\n";

echo "\$file2: " . $file2 . "\n\n";

echo "Position of \$file1's first '.' : " . strpos($file1, '.') . "\n";

echo "Position of \$file1's last  '.' : " . strripos($file1, '.') . "\n";

echo "Position of \$file2's first '.' : " . strpos($file2, '.') . "\n";

echo "Position of \$file2's last  '.' : " . strripos($file2, '.') . "\n\n";

if (strpos($file1, '.') != strripos($file1, '.'))

{

    echo "\$file1 has >= 2 dots\n";

}

else

{

    echo "\$file1 has 1 dot \n";

}

if (strpos($file2, '.') != strripos($file2, '.'))

{

    echo "\$file2 has >= 2 dots\n";

}

else

{

    echo "\$file2 has 1 dot \n";

}

输出：

$file1: hello.jpg

$file2: hello.file.jpg

Position of $file1's first '.' : 5

Position of $file1's last  '.' : 5

Position of $file2's first '.' : 5

Position of $file2's last  '.' : 10

$file1 has 1 dot

$file2 has >= 2 dots