【c#】c#中函数参数的注意事项

Dear 丶 2022-06-13 13:42 375阅读 0赞

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   <td style="border-style:solid; border-width:1px; border-color:rgb(211,211,211); padding:10px; margin:0px; width:99.8489425981873%"> 注意事项</td> 
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      1.参数数组 (params) 
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     <li>c#允许为函数指定<span style="color:rgb(255,70,53)">一个</span>（只能有一个）特殊参数，称为 “参数数组”</li> 
     <li>参数数组必须放在函数的<span style="color:rgb(255,0,0)">最后一个</span>参数</li> 
     <li>用 <span style="color:rgb(255,0,0)">params</span> 关键字修饰的数组是参数数组 &nbsp;(params int[] vals)</li> 
     <li>关键字params定义函数&nbsp;&nbsp;SumVals<span style="font-family:微软雅黑; widows:auto"><span style="font-size:14px">(params int[] vals</span>)</span>，可以接受任意个 int类型的参数</li> 
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      SumVals(2, 3, 4, 5); 
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      2.引用参数 (ref) 
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     <li>函数对引用参数进行操作可以<span style="color:rgb(255,0,0)">改变</span>所传参数的值</li> 
     <li>引用参数用 “<span style="color:rgb(255,70,53)">ref</span>”关键字修饰</li> 
     <li>引用参数不能为常量，<span style="color:rgb(255,0,0)">不能被“const”修饰</span></li> 
     <li>引用参数必须使用<span style="color:rgb(255,0,0)">初始化过</span>的变量</li> 
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       //函数 
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       static void ShowDouble(ref int val){} 
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       //调用 
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       int myNumber = 1; 
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       ShowDouble(ref myNumble) &nbsp;//调用时也要用ref 
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      3.输出参数 (out) 
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     <li>用out关键字，指定所给的参数是一个输出参数</li> 
     <li>函数用out修饰参数时，必须把它看作尚未赋值（即使存储变量的值，也会在函数执行时丢失）</li> 
     <li>在调用函数时也要用out，就像ref一样</li> 
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      4. =&gt;(Lambda箭头) 
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     <li>c#6 中引入的功能：执行一行代码的函数可用 =&gt; 来实现</li> 
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      例如： 
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      static string GetString() =&gt; return "Here is a string"; 
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     <li>c#6之前还是用 { }</li> 
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