32 lines
1.4 KiB
XML
32 lines
1.4 KiB
XML
<?xml version="1.0"?>
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<clause number="8.11" title="Enums" informative="true">
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<paragraph>An enum type declaration defines a type name for a related group of symbolic constants. Enums are used for "multiple choice" scenarios, in which a runtime decision is made from a fixed number of choices that are known at compile-time. </paragraph>
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<paragraph>The example <code_example><![CDATA[
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enum Color
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{
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Red,
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Blue,
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Green
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}
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class Shape
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{
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public void Fill(Color color) {
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switch(color) {
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case Color.Red:
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...
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break;
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case Color.Blue:
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...
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break;
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case Color.Green:
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...
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break;
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default:
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break;
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}
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}
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}
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]]></code_example>shows a Color enum and a method that uses this enum. The signature of the Fill method makes it clear that the shape can be filled with one of the given colors. </paragraph>
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<paragraph>The use of enums is superior to the use of integer constants-as is common in languages without enums-because the use of enums makes the code more readable and self-documenting. The self-documenting nature of the code also makes it possible for the development tool to assist with code writing and other "designer" activities. For example, the use of Color rather than <keyword>int</keyword> for a parameter type enables smart code editors to suggest Color values. </paragraph>
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</clause>
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