Zend supports the creation of true constants (as
opposed to regular variables). Constants are accessed without
the typical dollar sign (
$
) prefix and are available in all scopes. Examples include
TRUE
and
FALSE
, to name just two.
To create your own constants, you can use the
macros in
表33-6
. All the macros create a constant with the specified name and
value.
You can also specify flags for each constant:
CONST_CS
- This constant's name is to be treated as case
sensitive.
CONST_PERSISTENT
- This constant is persistent and won't be "forgotten" when
the current process carrying this constant shuts down.
// register a new constant of type "long" REGISTER_LONG_CONSTANT("NEW_MEANINGFUL_CONSTANT", 324, CONST_CS | CONST_PERSISTENT); |
表 33-6Macros for Creating Constants
Macro | Description |
REGISTER_LONG_CONSTANT(name, value, flags) REGISTER_MAIN_LONG_CONSTANT(name, value, flags) | Registers a new constant of type long. |
REGISTER_DOUBLE_CONSTANT(name, value, flags) REGISTER_MAIN_DOUBLE_CONSTANT(name, value, flags) | Registers a new constant of type double. |
REGISTER_STRING_CONSTANT(name, value, flags) REGISTER_MAIN_STRING_CONSTANT(name, value, flags) | Registers a new constant of type string. The specified string must reside in Zend's internal memory. |
REGISTER_STRINGL_CONSTANT(name, value, length, flags) REGISTER_MAIN_STRINGL_CONSTANT(name, value, length, flags) | Registers a new constant of type string. The string length is explicitly set to length . The specified string must reside in Zend's internal memory. |