无涯教程-C# - nested 循环函数 C#允许在一个循环中使用另一个循环，以下部分显示了几个示例来说明这一概念。

C#允许在一个循环中使用另一个循环，以下部分显示了几个示例来说明这一概念。

nested loops - 语法

C#中嵌套FOR LOOP语句的语法如下所示:-

for ( init; condition; increment ) {
   for ( init; condition; increment ) {
      statement(s);
   }
   statement(s);
}

C#中嵌套的WHILE LOOP语句的语法如下所示:-

while(condition) {
   while(condition) {
      statement(s);
   }
   statement(s);
}

C#中嵌套DO.WHILE LOOP语句的语法如下所示:-

do {
   statement(s);
   do {
      statement(s);
   }
   while( condition );
}
while( condition );

关于循环嵌套的最后一个注意事项是，您可以将任何类型的循环放在任何其他类型的循环中。如，for循环可以在while循环中，反之亦然。

下面的程序使用嵌套的FOR循环来查找从2到100-的素数

using System;
namespace Loops {
class Program {
static void Main(string[] args) {
/* 局部变量定义 */
int i, j;
     </span><span class="kwd">for</span><span class="pln"> </span><span class="pun">(</span><span class="pln">i </span><span class="pun">=</span><span class="pln"> </span><span class="lit">2</span><span class="pun">;</span><span class="pln"> i </span><span class="pun">&lt;</span><span class="pln"> </span><span class="lit">100</span><span class="pun">;</span><span class="pln"> i</span><span class="pun">++)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
        </span><span class="kwd">for</span><span class="pln"> </span><span class="pun">(</span><span class="pln">j </span><span class="pun">=</span><span class="pln"> </span><span class="lit">2</span><span class="pun">;</span><span class="pln"> j </span><span class="pun">&lt;=</span><span class="pln"> </span><span class="pun">(</span><span class="pln">i</span><span class="pun">/</span><span class="pln">j</span><span class="pun">);</span><span class="pln"> j</span><span class="pun">++)</span><span class="pln">
        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">((</span><span class="pln">i </span><span class="pun">%</span><span class="pln"> j</span><span class="pun">)</span><span class="pln"> </span><span class="pun">==</span><span class="pln"> </span><span class="lit">0</span><span class="pun">)</span><span class="pln"> </span><span class="kwd">break</span><span class="pun">;</span><span class="pln"> </span><span class="com">//如果找到因子，则不是素数</span><span class="pln">
        </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">j </span><span class="pun">&gt;</span><span class="pln"> </span><span class="pun">(</span><span class="pln">i</span><span class="pun">/</span><span class="pln">j</span><span class="pun">))</span><span class="pln"> </span><span class="typ">Console</span><span class="pun">.</span><span class="typ">WriteLine</span><span class="pun">(</span><span class="str">"{0} is prime"</span><span class="pun">,</span><span class="pln"> i</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="typ">Console</span><span class="pun">.</span><span class="typ">ReadLine</span><span class="pun">();</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">

}
}

编译并执行上述代码时，将生成以下输出-

2 is prime
3 is prime
5 is prime
7 is prime
11 is prime
13 is prime
17 is prime
19 is prime
23 is prime
29 is prime
31 is prime
37 is prime
41 is prime
43 is prime
47 is prime
53 is prime
59 is prime
61 is prime
67 is prime
71 is prime
73 is prime
79 is prime
83 is prime
89 is prime
97 is prime

无涯教程-C# - nested 循环函数

nested loops - 语法

参考链接