Php constant define () constant (), defined ()

Php constant define () constant (), defined () define-defines a constant. if true is defined, booldefine (stringname, mixedvalue [, boolcase_insensitive]) is not case sensitive during read. constants can only contain scalar data (boolean, integer, float php constants define () constant (), defined ()

Define-defines a constant. if it is set to true, the read process is case insensitive.

Bool define (string name, mixed value [, bool case_insensitive])

Constants can only contain scalar data (Boolean,Integer,FloatAndString).

Define ("CONSTANT", "Hello world .");
Echo CONSTANT; // outputs "Hello world ."
Echo Constant; // outputs "Constant" and issues a notice.

Define ("GREETING", "Hello you.", true );
Echo GREETING; // outputs "Hello you ."
Echo Greeting; // outputs "Hello you ."

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Constant ()-read constants

MixedConstant(String name)

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Define ("MAXSIZE", 100 );

Echo MAXSIZE;
Echo constant ("MAXSIZE"); // same thing as the previous line

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Defined-determines whether a constant is defined

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BoolDefined(String name)

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If (defined ('constant ')){
???? Echo CONSTANT;
}

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Predefined Constants

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_ FILE __?? Obtain the physical address of a file? Note: There are two underscores (_) between the left and right.

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Echo _ FILE __??? // C: \ wamp \ www \ T1 \ 1.php

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