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    <p>Several reasons:</p> <p><strong>Reason 1: Flexibility:</strong></p> <pre><code>enum lickahoctor { yes = 0, no = 1, maybe = 2 }; </code></pre> <p>declares an enumeration. You can use the values <code>yes</code>, <code>no</code> and <code>maybe</code> anywhere and assign them to any integral type. You can also use this as a type, by writing</p> <pre><code>enum lickahoctor myVar = yes; </code></pre> <p>This makes it nice because if a function takes a parameter with the type enum lickahoctor you'll know that you can assign <code>yes</code>, <code>no</code> or <code>maybe</code> to it. Also, the debugger will know, so it'll display the symbolic name instead of the numerical value. Trouble is, the compiler will only let you assign values you've defined in <code>enum lickahoctor</code> to <code>myVar</code>. If you for example want to define a few flags in the base class, then add a few more flags in the subclass, you can't do it this way.</p> <p>If you use an int instead, you don't have that problem. So you want to use some sort of int, so you can assign arbitrary constants.</p> <p><strong>Reason 2: Binary compatibility:</strong></p> <p>The compiler chooses a nice size that fits all the constants you've defined in an enum. There's no guarantee what you will get. So if you write a struct containing such a variable directly to a file, there is no guarantee that it will still be the same size when you read it back in with the next version of your app (according to the C standard, at least -- it's not quite that bleak in practice).</p> <p>If you use some kind of int instead, the platform usually guarantees a particular size for that number. Especially if you use one of the types guaranteed to be a particular size, like <code>int32_t</code>/<code>uint32_t</code>.</p> <p><strong>Reason 3: Readability and self-documentation</strong></p> <p>When you declare myVar above, it's immediately obvious what values you can put in it. If you just use an int, or an <code>uint32_t</code>, it isn't. So what you do is you use</p> <pre><code>enum { yes, no, maybe }; typedef uint32_t lickahoctor; </code></pre> <p>to define a nice name for the integer somewhere near the constants that will remind people that a variable of this type can hold this value. But you still get the benefit of a predictable, fixed size and the ability to define additional values in subclasses, if needed.</p> <p><strong>Reason 4: Support for bitfields</strong></p> <p>enum-typed variables only support assigning exactly one value from their options. So if you're trying to implement a bit field, you can't type it as a bitfield. Furthermore, you need to use unsigned variables to avoid sign extension from screwing you over.</p>
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    1. POWhy doesn't cocoa use the same enum declaration style everywhere?
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      1. VTUpMod
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    1. CONSInteger isn't guaranteed to be a particular size, it's guaranteed to be different on `i386` and `x86_64`. If you wrote out a binary file with a `lickahoctor` in on a Core Duo, upgraded your Mac and read it back in, hilarity would ensue.
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    2. COOf course, Graham. Brainfart there. Thanks for correcting that.
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    3. CO+1 for `lickahoctor`, even though it is an inside joke.
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