Strcmp函数实现

int StrCmp( const char * des, const char * src)
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedBloc
kStart.gif) ![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/
ContractedBlock.gif) … {

int c;

if (des == NULL || src == NULL)

throw " NULL point " ;

int len1 = strlen(des);

int len2 = strlen(src);

if (len1 != len2)
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockStart.gif) ![](http://images.csdn.net/syntaxhighlighting/OutliningIndicato
rs/ContractedSubBlock.gif) … {

return len1 - len2;
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockEnd.gif) }

while ( * des != ’ /0 ’ )
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockStart.gif) ![](http://images.csdn.net/syntaxhighlighting/OutliningIndicato
rs/ContractedSubBlock.gif) … {

if ((c = ( * des ++ - * src ++ )) != 0 )
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockStart.gif) ![](http://images.csdn.net/syntaxhighlighting/OutliningIndicato
rs/ContractedSubBlock.gif) … {

return c;
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockEnd.gif) }
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedSubB
lockEnd.gif) }

return c;
![](http://images.csdn.net/syntaxhighlighting/OutliningIndicators/ExpandedBloc
kEnd.gif) }

测试用例：

1.字符串为AscII串，并且src和des不为空，测试中以src和des长度分类

2.字符串为高AscII串…

3.字符串为DBCS串

4.字符串中包含DBCS和ASCII

5.src或者des为NULL

6.src和des为""