It defines a constant

Example

<?php
define(“LAN”,”phpcode”);
echo constant(“LAN”);
?>

Output

phpcode

It returns the value of a constant

Example

<?php
define(“LAN”,”phpcode”);
echo constant(“LAN”);
?>

Output

phpcode

It checks if the script timed out

Example

<?php
if(connection_timeout())
echo “Timed out”;
?>

Its deprecated in PHP 4.0.5

It returns the current connection status

Example

<?php
echo connection_status ();
?>

It returns one of the follows

0 – CONNECTION_NORMAL – connection is running normally
1 – CONNECTION_ABORTED – connection is aborted by user or network error
2 – CONNECTION_TIMEOUT –  connection timed out
3 – CONNECTION_ABORTED & CONNECTION_TIMEOUT

• connection_aborted() – It checks whether the client has disconnected.
• connection_status() – It returns the current connection status
• connection_timeout() – It checks if the script timed out
• constant() – It returns the value of a constant
• define() – It defines a constant
• defined() – It checks whether a given named constant exists
• die() – Its an  alias of the exit() and prints a message and exits the current script
• eval() – It evaluates a string as PHP code.
• exit() – It output a message and terminate the current script
• get_browser() – It returns the capabilities of the user’s browser
• __halt_compiler() – It halts the compiler execution
• highlight_file() – It outputs a file with the PHP syntax highlighted
• highlight_string() – It outputs a string with the PHP syntax highlighted
• ignore_user_abort() – It sets whether a remote client can abort the running of a script
• pack() – It packs data into a binary string
• php_check_syntax() – It heck the PHP syntax of  the specified file
• php_strip_whitespace() – It returns the source code of a file with PHP comments and whitespace removed
• show_source() – Its an alias of highlight_file() and outputs a file with the PHP syntax highlighted
• sleep() – It delays execution
• sys_getloadavg() – It returns system load average
• time_nanosleep() – It delay for a number of seconds and nanoseconds
• time_sleep_until() – It makes the script sleep until the specified time
• uniqid() – It generates a unique ID
• unpack() – It unpacks data from binary string
• usleep() – It delays execution in microseconds