php detects whether file exists

Under normal circumstances, it is no problem to use file_exists to check whether the file exists, but one thing to note is that it will return false when the safe mode and directory do not have execution permissions.

##file_exists: Check whether the file exists or whether the directory exists; (Recommended learning: Getting Started with PHP Programming To master )

$file = "check.txt";

if(file_exists($file))
{
    echo "当前目录中，文件".$file."存在";
}
else
{
     echo "当前目录中，文件".$file."不存在";
}

is_file Determine whether the file exists and check whether the specified file name is a normal file;

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

Note: The results of this function will be cached. Please use clearstatcache() to clear the cache.

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, ## The #file_exits function will not affect the speed depending on whether the file actually exists, but the impact of is_file will be greater.

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