📄 c-c+语言struct深层探索 - k的专栏 - csdnblog.htm
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face="Times New Roman">8. struct example2 </FONT></SPAN></P>
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style="FONT-SIZE: 12pt; BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto"><FONT
face="Times New Roman">9. { </FONT></SPAN></P>
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style="mso-tab-count: 1"> </SPAN>10.
char c; </FONT></SPAN></P>
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style="mso-tab-count: 1"> </SPAN>11.
example1 struct1; </FONT></SPAN></P>
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style="mso-tab-count: 1"> </SPAN>12.
short e;<SPAN style="mso-spacerun: yes">
</SPAN></FONT></SPAN></P>
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style="FONT-SIZE: 12pt; BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto"><FONT
face="Times New Roman">13. }; </FONT></SPAN></P>
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face="Times New Roman">14. #pragma pack() </FONT></SPAN></P>
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style="FONT-SIZE: 12pt; BACKGROUND: #d9d9d9; mso-shading: white; mso-pattern: gray-15 auto"><FONT
face="Times New Roman">15. int main(int argc, char* argv[])
</FONT></SPAN></P>
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face="Times New Roman">16. { </FONT></SPAN></P>
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face="Times New Roman"><SPAN
style="mso-tab-count: 1"> </SPAN>17.
example2 struct2; </FONT></SPAN></P>
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face="Times New Roman"><SPAN
style="mso-tab-count: 1"> </SPAN>18.
cout << sizeof(example1) << endl; </FONT></SPAN></P>
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face="Times New Roman">19. cout << sizeof(example2) << endl;
</FONT></SPAN></P>
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style="mso-tab-count: 1"> </SPAN>20.
cout << (unsigned int)(&struct2.struct1) - (unsigned
int)(&struct2) </FONT></SPAN></P>
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face="Times New Roman"><< endl; </FONT></SPAN></P>
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style="mso-tab-count: 1"> </SPAN>21.
return 0; </FONT></SPAN></P>
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face="Times New Roman">22. } </FONT></SPAN></P>
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style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">问程序的输入结果是什么？</SPAN><SPAN
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<P class=MsoNormal
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style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">答案是：</SPAN><SPAN
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</FONT></SPAN></P>
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</FONT></SPAN></P>
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<P class=MsoNormal
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lang=EN-US style="FONT-SIZE: 12pt"><FONT face="Times New Roman">4
</FONT></SPAN></P>
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<P class=MsoNormal
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style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">不明白？还是不明白？下面一一道来：</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"> </SPAN></P>
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<P class=MsoNormal style="MARGIN: 0cm 0cm 0pt"><STRONG
style="mso-bidi-font-weight: normal"><SPAN lang=EN-US
style="FONT-SIZE: 12pt"><FONT face="Times New Roman">2.1
</FONT></SPAN></STRONG><STRONG style="mso-bidi-font-weight: normal"><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">自然对界</SPAN></STRONG><STRONG
style="mso-bidi-font-weight: normal"><SPAN lang=EN-US
style="FONT-SIZE: 12pt"> </SPAN></STRONG></P>
<P> </P>
<P class=MsoNormal
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lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">struct</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">是一种复合数据类型，其构成元素既可以是基本数据类型（如</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">int</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">long</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">float</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">等）的变量，也可以是一些复合数据类型（如</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">array</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">struct</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">、</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT
face="Times New Roman">union</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">等）的数据单元。对于结构体，编译器会自动进行成员变量的对齐，以提高运算效率。缺省情况下，编译器为结构体的每个成员按其自然对界（</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT face="Times New Roman">natural
alignment</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">）条件分配空间。各个成员按照它们被声明的顺序在内存中顺序存储，第一个成员的地址和整个结构的地址相同。</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"> </SPAN></P>
<P> </P>
<P class=MsoNormal
style="MARGIN: 0cm 0cm 0pt; TEXT-INDENT: 24pt; mso-char-indent-count: 2.0"><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">自然对界</SPAN><SPAN
lang=EN-US style="FONT-SIZE: 12pt"><FONT face="Times New Roman">(natural
alignment)</FONT></SPAN><SPAN
style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">即默认对齐方式，是指按结构体的成员中</SPAN><SPAN
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