46 lines
1.6 KiB
C#
46 lines
1.6 KiB
C#
//-- ex-nullable
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using System;
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class MyTest {
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public static void Main(String[] args) {
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Console.WriteLine("Note that null prints as blank or []\n");
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int? i1 = 11, i2 = 22, i3 = null, i4 = i1+i2, i5 = i1+i3;
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// Values: 11 22 null 33 null
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Console.WriteLine("[{0}] [{1}] [{2}] [{3}] [{4}]", i1, i2, i3, i4, i5);
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int i6 = (int)i1; // Legal
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// int i7 = (int)i5; // Legal but fails at run-time
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// int i8 = i1; // Illegal
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int?[] iarr = { i1, i2, i3, i4, i5 };
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i2 += i1;
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i2 += i4;
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Console.WriteLine("i2 = {0}", i2); // 66 = 11+22+33
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int sum = 0;
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for (int i=0; i<iarr.Length; i++)
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sum += iarr[i] != null ? iarr[i].Value : 0;
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// sum += iarr[i] ?? 0;
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Console.WriteLine("sum = {0}", sum); // 66 = 11+22+33
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for (int i=0; i<iarr.Length; i++)
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if (iarr[i] > 11)
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Console.Write("[{0}] ", iarr[i]); // 22 33
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Console.WriteLine();
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for (int i=0; i<iarr.Length; i++)
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if (iarr[i] != i1)
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Console.Write("[{0}] ", iarr[i]); // 22 null 33 null
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Console.WriteLine();
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Console.WriteLine();
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int?[] ivals = { null, 2, 5 };
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Console.WriteLine("{0,6} {1,6} {2,6} {3,6} {4,-6} {5,-6} {6,-6} {7,-6}",
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"x", "y", "x+y", "x-y", "x<y", "x>=y", "x==y", "x!=y");
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Console.WriteLine();
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foreach (int? x in ivals)
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foreach (int? y in ivals)
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Console.WriteLine("{0,6} {1,6} {2,6} {3,6} {4,-6} {5,-6} {6,-6} {7,-6}",
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x, y, x+y, x-y, (x<y), (x>=y), x==y, x!=y);
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}
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}
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