为什么/如何在函数中使用传递的常量？ [英] Why/How to use passed constants in function?

问题描述

我已经看过常量传递给方法的类，我想它在该函数中定义了一些设置。我不能找到它在任何地方，试图找出逻辑，所以我虽然我可以问这里。如何和为什么使用这个概念，我在哪里可以找到更多的信息？

I've seen classes where constants are passed to methods, I guess its done to define some kind of setting in that function. I cant find it anywhere now to try to find out the logic, so I though I could ask here. How and why do you use this concept and where can I find more information about it?

下面的例子是用PHP编写的，但任何处理常量的语言都可以。

The example below is written in PHP, but any language that handles constants would do I guess..

// Declaring class
class ExampleClass{
  const EXAMPLE_CONST_1 = 0;
  const EXAMPLE_CONST_2 = 1;  

  function example_method($constant(?)){

     if($constant == ExampleClass::EXAMPLE_CONST_1)
       // do this
     else if($constant == ExampleClass::EXAMPLE_CONST_2)
       // do that

  }
}

// Using class
$inst = new ExampleClass();
$inst->example_method(ExampleClass::EXAMPLE_CONST_1);

对我来说，比传递1更清楚地传递ExampleClass :: EXAMPLE_CONST_1但是这是传递常量的唯一原因？

To me its more clear to pass "ExampleClass::EXAMPLE_CONST_1" than to just pass "1", but it's that the only reason to pass constant?

推荐答案

简单地传递1不说太多。

Simply passing 1 doesn't say much. By having a constant you can have a description about the settings in the name.

例如：
constant RAIN = 1;

example: constant RAIN = 1;

方法setWeather（RAIN）;

method setWeather(RAIN);

至少这是我使用它的方式和原因。

Atleast that's how and why I use it.

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