怎样进行两个字符串相减？

[laodiao]

怎样进行两个字符串相减？
s1:="chian ren"
s2:="china"

[王集鹄]

s1:="chian ren"
s2:="china"
结果是什么？

s1:="chian ren"
s2:="china "
结果是什么？

s1:="chian ren"
s2:="aachina"
结果是什么？

[laodiao]

s3:=s1-s2

应该是 ren

[tygh2000]

呵呵，问得好！

[laodiao]

怎样去计算呢?

[光明山人]

请问： "abcd" - "wxyz" 应该等于多少？

[王集鹄]

弄清楚你要什么先
"abc" - "ac" = ?
"ab" - "ac" = ?
"abcd" - " bcd" = ?

[laodiao]

s2,s1其中s2是s1的子串，所以需要将

[zhuzhuer]

直接减就可以了，但关键是你要弄清楚你究竟想得到什么样的结果，呵呵

[王集鹄]

s3 := StringReplace(s1, s2, '', [rfReplaceAll]);
//删除s1中s2子串

[delphi_xizhousheng]

还有和笨办法，就是将S1，S2分解为[‘C’，‘H’。。。。]和[‘C’，‘H’。。。。]的集合，再用S1-S2，
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪
倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪
倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪磊磊磊磊倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪磊磊磊倪
倪磊磊磊倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪磊磊磊倪
倪磊磊磊倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪磊磊磊倪
倪磊磊磊倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪磊磊磊倪
倪磊磊磊倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪磊磊磊倪
倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪
倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪磊磊磊磊磊磊磊磊倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪磊磊倪倪倪倪磊磊倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪磊磊倪倪倪倪磊磊倪倪倪倪倪磊磊磊倪倪倪
倪倪倪磊磊磊倪倪倪倪倪磊磊倪倪倪倪磊磊倪倪磊倪倪磊磊磊倪倪倪
倪倪磊磊磊倪倪倪倪倪倪磊磊磊磊磊磊磊磊倪倪磊磊倪磊磊磊倪倪倪
倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊磊磊倪倪倪
磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊磊倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪磊磊磊磊倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪磊磊磊倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪磊磊倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪倪
倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪倪
倪倪磊磊倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪磊磊倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
磊倪倪倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪倪倪倪
倪倪倪倪倪倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪倪倪倪倪倪倪倪倪倪倪倪倪倪磊磊磊倪倪倪倪倪倪倪倪倪倪倪倪倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊磊倪
倪倪倪倪倪倪

[zhptj]

我看还是先判断是否存在包含关系，然后再进行减法

[qybao]

s1:='china ren'
s2:='china'
结果是什么？'ren'如果是这样
zswang(伴水)(* 嘻嘻 *)的方法不错
if Pos(s2,s1)>0 then
s3 := StringReplace(s1, s2, '', [rfReplaceAll]);
有没有这种情况:
s1:='china ren china'
s2:='china'
相减是'china ren' 或'ren china'?