Php constants and php constants _ PHP Tutorial

Php constants and php constants. Php constants. which define () functions of php constants are used to define constants. Once a constant is defined, it cannot be changed or undefined. Example of defining constants :? Phpdefine (CONSTA php constant, which php constants are there?

The define () function is used to define constants. Once a constant is defined, it cannot be changed or undefined.

Example of defining constants:

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Constant names and any other PHP labels follow the same naming rules. A valid constant name starts with a letter or underline followed by any letter, number, or underline.

Constants are case-sensitive by default, and constant identifiers are always capitalized. this value cannot be changed during script execution.

Differences between defining constants and variables:

• No dollar sign before a constant ($)
• Constants can only be defined using the define () function, but cannot be defined using the value assignment statement.
• Constants can be defined and accessed anywhere, regardless of the variable range rules.
• Once defined, a constant cannot be redefined or undefined.
• The constant value can only be a scalar.

PHP has a large number of predefined constants. For more information, see The PHP Manual.

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The includefine () function is used to define constants. Once a constant is defined, it cannot be changed or undefined. Example of defining constants :? Phpdefine ("CONSTA...