The difference between is_file, file_exists and is_dir in php_PHP tutorial

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Release: 2016-07-13 16:56:36
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This article introduces the difference between is_file, file_exists and is_dir in php. Friends in need can refer to it.

is_file only determines whether the file exists;

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The code is as follows
 代码如下 复制代码


$file = "test.txt";   
if(is_file($file)) {   
echo ("$file is a regular file");   
}else {   
echo ("$file is not a regular file");   
}   
?>   

输出:test.txt is a regular file

Copy code

 代码如下 复制代码

echo file_exists("test.txt");
?>

输入

1

$file = "test.txt";

if(is_file($file)) {  

echo ("$file is a regular file");
代码如下 复制代码

$file = "images";
if(is_dir($file))
{
echo ("$file is a directory");
}
else
{
echo ("$file is not a directory");
}
?>

输出:

images is a directory

}else {  

echo ("$file is not a regular file");

}  

?>  

Output: test.txt is a regular file

file_exists determines whether the file or directory exists;
 代码如下 复制代码

文件存在(当前目录)
is_file:0.4570ms
file_exists:2.0640ms
文件存在(绝对路径3层/www/hx/a/)
is_file:0.4909ms
file_exists:3.3500ms
文件存在(绝对路径5层/www/hx/a/b/c/)
is_file:0.4961ms
file_exists:4.2100ms
文件不存在(当前目录)
is_file:2.0170ms
file_exists:1.9848ms
文件不存在(绝对路径5层/www/hx/a/b/c/)
is_file:4.1909ms
file_exists:4.1502ms
目录存在
file_exists:2.9271ms
is_dir:0.4601ms
目录不存在
file_exists:2.9719ms
is_dir:2.9359ms

The code is as follows Copy code
echo file_exists("test.txt");
?>Enter 1 is_dir determines 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 Looking at the manual, although the results of these two functions will be cached, is_file is N times faster. One more thing worth noting: When the file exists, is_file is N times faster than file_exists; When the file does not exist, is_file is slower than file_exists; The conclusion is that the file_exits function does not affect the speed depending on whether the file actually exists, but the impact of is_file is greater Test
The code is as follows Copy code
File exists (current directory) is_file:0.4570ms file_exists:2.0640ms File exists (absolute path level 3/www/hx/a/) is_file:0.4909ms file_exists:3.3500ms The file exists (absolute path level 5/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 The file does not exist (absolute path level 5/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.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/631588.htmlTechArticleThis article introduces the difference between is_file, file_exists and is_dir in php. Friends in need can refer to it. is_file only determines whether the file exists; the code is as follows Copy the code ?php $file =...