tests/gtest-131.cs

   1 //-- ex-nullable
   2
   3 using System;
   4
   5 class MyTest {
   6   public static void Main(String[] args) {
   7     Console.WriteLine("Note that null prints as blank or []\n");
   8     int? i1 = 11, i2 = 22, i3 = null, i4 = i1+i2, i5 = i1+i3;
   9     // Values: 11 22 null 33 null
  10     Console.WriteLine("[{0}] [{1}] [{2}] [{3}] [{4}]", i1, i2, i3, i4, i5);
  11     int i6 = (int)i1;                           // Legal
  12     // int i7 = (int)i5;                        // Legal but fails at run-time
  13     // int i8 = i1;                             // Illegal
  14
  15     int?[] iarr = { i1, i2, i3, i4, i5 };
  16     i2 += i1;
  17     i2 += i4;
  18     Console.WriteLine("i2 = {0}", i2);          // 66 = 11+22+33
  19
  20     int sum = 0;
  21     for (int i=0; i<iarr.Length; i++)
  22       sum += iarr[i] != null ? iarr[i].Value : 0;
  23       //      sum += iarr[i] ?? 0;
  24     Console.WriteLine("sum = {0}", sum);        // 66 = 11+22+33
  25
  26     for (int i=0; i<iarr.Length; i++)
  27       if (iarr[i] > 11)
  28         Console.Write("[{0}] ", iarr[i]);       // 22 33
  29     Console.WriteLine();
  30
  31     for (int i=0; i<iarr.Length; i++)
  32       if (iarr[i] != i1)
  33         Console.Write("[{0}] ", iarr[i]);       // 22 null 33 null
  34     Console.WriteLine();
  35     Console.WriteLine();
  36     int?[] ivals = { null, 2, 5 };
  37     Console.WriteLine("{0,6} {1,6} {2,6} {3,6} {4,-6} {5,-6} {6,-6} {7,-6}",
  38                       "x", "y", "x+y", "x-y", "x<y", "x>=y", "x==y", "x!=y");
  39     Console.WriteLine();
  40     foreach (int? x in ivals)
  41       foreach (int? y in ivals)
  42         Console.WriteLine("{0,6} {1,6} {2,6} {3,6} {4,-6} {5,-6} {6,-6} {7,-6}",
  43                           x, y, x+y, x-y, (x<y), (x>=y), x==y, x!=y);
  44   }
  45 }