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//这是常规思路:
const
  arr: array[0..1] of Char = ('A','B');
begin
  ShowMessage(arr);                   {AB}
  ShowMessage(IntToStr(Length(arr))); {2}
end;

//没想到可以这样: const arr: array[Boolean] of Char = ('A','B'); begin ShowMessage(arr); {AB} ShowMessage(IntToStr(Length(arr))); {2} {访问元素} ShowMessage(arr[False]); {A} ShowMessage(arr[True]); {B} {也可以这样访问} ShowMessage(arr[Low(arr)]); {A} ShowMessage(arr[High(arr)]); {B} {但不能这样访问} // ShowMessage(arr[0]); // ShowMessage(arr[1]); {但可以变通一下} ShowMessage(arr[Boolean(0)]); {A} ShowMessage(arr[Boolean(1)]); {B} end;
//同理, 这样也可以: const arr: array[Byte] of Integer = ( 1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29, 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55, 56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81, 82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105, 106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125, 126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,144,145, 146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,162,163,164,165, 166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,181,182,183,184,185, 186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205, 206,207,208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,224,225, 226,227,228,229,230,231,232,233,234,235,236,237,238,239,240,241,242,243,244,245, 246,247,248,249,250,251,252,253,254,255,256); begin ShowMessage(IntToStr(arr[Low(arr)])); {1} ShowMessage(IntToStr(arr[High(arr)])); {256} ShowMessage(IntToStr(Length(arr))); {256} end;
//给这种用法来一个必要性的实例: const BoolStr: array[Boolean] of string = ('False', 'True'); var b: Boolean; begin b := True; ShowMessage(BoolStr[b]); {True} b := not b; ShowMessage(BoolStr[b]); {False} end;
posted on 2008-04-17 15:01  万一  阅读(...)  评论(...编辑  收藏