(原創) 如何将字符串前后的空白去除? (使用string.find_first_not_of, string.find_last_not_of) (C/C++)
这在字符串处理是很常用的功能,.NET Framework的String class直接提供Trim()的method,其它语言也大都有提供(VB、VFP),但C++无论Standard Library或STL都找不到相对应方法,以下的方式是由希冀blog中的C++中如何去掉std::string对象的首尾空格 改编而来,加上了pass by reference适合function使用,其中std::string所提供的find_first_not_of()和find_last_not_of()真是大开眼界,竟然还有这种method,可以找寻第一个不符合条件的位置,我在其它语言都还没见过这样的function。
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/*
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(C) OOMusou 2006 http://oomusou.cnblogs.com
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Filename : StringTrim1.cpp
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Compiler : Visual C++ 8.0
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Description : Demo how to trim string by find_first_not_of & find_last_not_of
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Release : 11/17/2006
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*/
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#include <iostream>
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#include <string>
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std::string& trim(std::string &);
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int main() {
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std::string s = " Hello World!! ";
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std::cout << s << " size:" << s.size() << std::endl;
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std::cout << trim(s) << " size:" << trim(s).size() << std::endl;
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return 0;
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}
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std::string& trim(std::string &s) {
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if (s.empty()) {
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return s;
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}
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s.erase(0,s.find_first_not_of(" "));
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s.erase(s.find_last_not_of(" ") + 1);
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return s;
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}
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See Also
(原創) 如何将字符串前后的空白去除? (使用template,可去whitespace) (C/C++) (template)
(原創) 如何將字串前後的空白去除? (C++) (boost)
Reference
C++中如何去掉std::string对象的首尾空格