php if exists

1, Case: Copy CodeThe code is as follows: $file = ' jb51.net.php '; if (is_readable ($file) = = False) { Die (' file does not exist or cannot be read '); } else { echo ' presence '; } ?> The is_readable () function determines whether the

: This article mainly introduces php programming notes. if you are interested in PHP tutorials, please refer to them. Three methods for php to obtain POST data Php image watermarking source code Php + ajax + json is the simplest example. Php Chinese

Php programming notes-three methods for obtaining POST data from small_123 php Php image watermarking source code Php + ajax + json is the simplest example. Php Chinese character to pinyin source code Php traverses the Directory, generates the md5

Three ways to get post data from PHP PHP image plus watermark source code One of the simplest examples of Php+ajax+json PHP Chinese Pinyin Source code PHP iterates through directories, generates MD5 values for each file in the directory, and writes

The following is an example code that checks whether a file exists: Copy CodeThe code is as follows: $filename = '/path/to/foo.txt '; if (file_exists ($filename)) { echo "The file $filename exists"; } else { echo "The file $filename does not exist"

PHP uses the In_array function to check if a value exists in the array This article mainly introduces PHP using the In_array function to check if there is a value in the array, a more detailed analysis of the function of the In_array function,

PHP Functions: Empty () and isset () are the functions that determine whether a variable has been configured, but there are certain differences when used. The empty () function is used to test whether a variable has been configured. Returns a value

fopen () method The simplest way is to use fopen (), to see if the file can be opened, can hit the file of course exists. The fopen () function opens the file or URL. If the open fails, the function returns FALSE. Syntax: fopen

PHP Array_key_exists An implementation method that checks whether a key name or index exists in an array, arraykeyexists Array_key_exists () The PHP array_key_exists () function is used to check if the given key name or index exists in the array

Contents of this section: PHP array function array_key_exists ()Array_key_exists () defines and uses the array_key_exists () function to determine whether a specified key exists in an array, returns TRUE if the key exists, or false otherwise.The