The difference between Is_file and file_exists and Is_dir in PHP _php tutorial

This article introduces the differences between Is_file and File_exists and Is_dir in PHP, and the friends who need them can refer to them.

Is_file only determine if the file exists;

The code is as follows	Copy Code
$file = "Test.txt"; if (Is_file ($file)) { Echo ("$file is a regular file"); }else { Echo ("$file is not a regular file"); } ?> Output: Test.txt is a regular file

File_exists determine whether the file exists or whether the directory exists;

The code is as follows	Copy Code
Echo file_exists ("test.txt"); ?> Input 1

Is_dir determine whether the directory exists;

Example

The code is as follows	Copy Code
$file = "Images"; if (Is_dir ($file)) { Echo ("$file is a directory"); } Else { Echo ("$file is not a directory"); } ?> Output: Images is a directory

Look at the manual, although the results of both functions are cached, but the is_file is almost n times faster.

There is one more notable:

In the case of file existence, Is_file is faster n times than file_exists;
If the file does not exist, Is_file is slower than file_exists;
The conclusion is that the File_exits function does not affect speed because the file does exist, but the is_file effect is large.

Test

The code is as follows

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File exists (current directory) Is_file:0.4570ms File_exists:2.0640ms File exists (absolute path 3 layer/www/hx/a/) Is_file:0.4909ms File_exists:3.3500ms File exists (absolute path 5 layer/www/hx/a/b/c/) Is_file:0.4961ms File_exists:4.2100ms File does not exist (current directory) Is_file:2.0170ms File_exists:1.9848ms File does not exist (absolute path 5 layer/www/hx/a/b/c/) Is_file:4.1909ms File_exists:4.1502ms Directory exists File_exists:2.9271ms Is_dir:0.4601ms Directory does not exist File_exists:2.9719ms Is_dir:2.9359ms

http://www.bkjia.com/PHPjc/631588.html www.bkjia.com true http://www.bkjia.com/PHPjc/631588.html techarticle This article introduces the differences between Is_file and File_exists and Is_dir in PHP, and the friends who need them can refer to them. Is_file only determine if the file exists; The code is copied code as follows? PHP $file = ...

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