delphi 判断一个数组的长度用 Length 还是 SizeOf ?？

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const

arr1: array[0..9] of Integer = (1,2,3,4,5,6,7,8,9,10);

arr2: array[0..1, 0..3] of Integer = ((1,2,3,4), (5,6,7,8));

var

arr3: array[Boolean] of Integer;

arr4: array[Byte] of Integer;

begin

ShowMessage(IntToStr(Length(arr1))); {10}

ShowMessage(IntToStr(SizeOf(arr1))); {40}

ShowMessage(IntToStr(Length(arr2))); {2}

ShowMessage(IntToStr(Length(arr2[0]))); {4}

ShowMessage(IntToStr(Length(arr2[1]))); {4}

ShowMessage(IntToStr(SizeOf(arr2))); {32}

ShowMessage(IntToStr(Length(arr3))); {2}

ShowMessage(IntToStr(SizeOf(arr3))); {8}

ShowMessage(IntToStr(Length(arr4))); {256}

ShowMessage(IntToStr(SizeOf(arr4))); {1024}

end;

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我们倒是可以利用这个原理, 迅速知道多维数组的元素总数:

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const

arr: array[0..1, 0..2, 0..3] of Integer =

(((1,1,1,1), (2,2,2,2), (3,3,3,3)), ((4,4,4,4), (5,5,5,5), (6,6,6,6)));

begin

ShowMessage(IntToStr(SizeOf(arr) div SizeOf(Integer))); {24}

end;