PHP function introduction—is_dir(): Check whether the path is a directory

PHP function introduction—is_dir(): Check whether the path is a directory

In PHP, it is often necessary to determine whether a path is a directory. At this time, you can use the is_dir() function to check. The function of is_dir() function is to determine whether the specified path is a directory and return a Boolean value to represent the result.

The following is the basic syntax of the is_dir() function:
bool is_dir (string $filename)

$isDir = is_dir($filename);
Among them, the $filename parameter is The path to be checked can be a relative path or an absolute path. The function returns a Boolean value, true if the path is a directory, false otherwise.

Now, let’s look at a specific example:
$dir = "test_dir";
if (is_dir($dir)) {

echo "路径 {$dir} 是一个目录";

} else {

echo "路径 {$dir} 不是一个目录";

}
?>
In the above example, we first define a variable $dir and assign it a path string "test_dir". Then, use the is_dir() function to determine whether the path is a directory. If it is a directory, output "the path test_dir is a directory"; otherwise, output "the path test_dir is not a directory".

In addition to the above examples, the is_dir() function can also be used with other functions, for example, combining the opendir() function and the readdir() function to traverse the files in the directory:

php
$dir = "test_dir";
if (is_dir($dir)) {

$handle = opendir($dir);
while (($file = readdir($handle)) !== false) {
    if ($file != "." && $file != "..") {
        echo "$file

";

    }
}
closedir($handle);

}
?>
at In the above example, we first use the is_dir() function to determine whether the specified path $dir is a directory. If it is a directory, call the opendir() function to open the directory and return a directory handle. Then use the readdir() function to traverse the directory file in, output the file name (except . and ..). Finally, close the directory handle and release resources by calling the closedir() function.

Summary:
is_dir() function is a commonly used PHP Function, used to determine whether a path is a directory. Use this function to quickly determine the type of file or directory, so as to make corresponding processing according to the actual situation. This article provides the basic syntax of the is_dir() function and gives a A simple example and an example of traversing a directory, I hope it will be helpful to readers when using this function.

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