Use of constant in php
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A constant is an identifier (name) for a simple value. As the name suggests, that value cannot change during the execution of the script (except for magic constants, which aren't actually constants). Constants are case-sensitive. By convention, constant identifiers are always uppercase. Show
The name of a constant follows the same rules as any label in PHP. A valid constant name starts with a letter or underscore, followed by any number of letters, numbers, or underscores. As a regular expression, it would be expressed thusly: It is possible to define() constants with reserved or even invalid names, whose value can only be retrieved with the constant() function. However, doing so is not recommended. Example #1 Valid and invalid constant names
Like superglobals, the scope of a constant is global. Constants can be accessed from anywhere in a script without regard to scope. For more information on scope, read the manual section on variable scope.
wbcarts at juno dot com ¶ 10 years ago
('MIN_VALUE', '0.0'); // RIGHT - Works OUTSIDE of a class definition.
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MAX_VALUE = 10; Sumon Mahmud (Abu Taleb) ¶ 2 years ago
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DEBUG) {
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constant('echo'); // outputs 'My constant value' What is the use of constant?Using a constant instead of specifying the same value multiple times can simplify code maintenance (as in don't repeat yourself) and can be self documenting by supplying a meaningful name for a value, for instance, PI instead of 3.1415926.
Can we use const in PHP?PHP introduced a keyword const to create a constant. The const keyword defines constants at compile time. It is a language construct, not a function. The constant defined using const keyword are case-sensitive.
What is the use of constant in OOP?Constants cannot be changed once it is declared. Class constants can be useful if you need to define some constant data within a class. A class constant is declared inside a class with the const keyword.
What is difference between constant and define in PHP?The basic difference between these two is that const defines constants at compile time, whereas define() defines them at run time. We can't use the const keyword to declare constant in conditional blocks, while with define() we can achieve that.
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