Summary of commonly used PHP system constants_PHP tutorial

The following are some commonly used PHP system constants:

__FILE__ current PHP file name

__LINE__ in the current PHP file Number of lines

__FUNCTION__ Currently executed function

__CLASS__ Currently executed class

PHP_VERSION PHP version

PHP_OS Current server operating system

TRUE Same as true

FALSE Same as false

E_ERROR Go to the nearest error location

E_WARNING Go to the nearest warning location

E_PARSE Syntax error There is an exception in

E_NOTICE in PHP language

M__PI Pi

M__E Scientific constant e

M__LOG2E Logarithm of e with base 2

M_LOG10E The logarithm of e with base 10

M_LN2 The natural logarithm of 2

M_LN10 The natural logarithm of 10

The content of PHP system constants is introduced Here, I hope it will be helpful to everyone.