Using PHP file_exists() to Check Files and Directories

In PHP programming, the file_exists() function is used to determine whether a specified file or directory exists.

Syntax: bool file_exists ( string $filename ) Parameter: $filename: the path of the file or directory to check.

Return value: Returns true if the file or directory exists, otherwise false.

Example: The following code demonstrates checking both a file and a directory.

<?php
// Check if a file exists
$file = 'example.txt';
if (file_exists($file)) {
    echo "文件存在。";
} else {
    echo "文件不存在。";
}

// Check if a directory exists
$dir = 'example_dir';
if (file_exists($dir) && is_dir($dir)) {
    echo "目录存在。";
} else {
    echo "目录不存在。";
}
?>

The example first defines a file path variable $file and uses file_exists() to verify its existence, outputting a corresponding message.

It then defines a directory path variable $dir and uses both file_exists() and is_dir() to confirm the directory’s presence before printing the result.

Notes:

The function can check local files, directories, or remote URLs.

It does not differentiate between files and directories; both return true when they exist.

It only reports existence, not accessibility; consider using is_readable() or is_writable() for permission checks.

Summary: file_exists() is a fundamental PHP function for verifying the existence of files or directories, returning a boolean value, and can be combined with other file‑handling functions to build robust file system operations.

php8，我来也

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