打印出系统时间优点：利用系统函数,还能修改系统时间，此文件必须是c++文件#include<cstdlib>#include<iostream>usingnamespacestd;voidmain(){system("time");}运行效果如下：但是如果system里面的参数变为：time/t，就不允许修改系统时间了(缺点：仅仅显示小时和分钟)#include<iostream>usingnamespacestd;voidmain(){system("time/t");system("pause");}改变DOS字体颜色#include<iostream>usingnamespacestd;voidmain(){system("colorob");system("pause");}注：当system(“colorob”)中的ob变为相应的数字时，DOS屏幕字体变为相应的颜色改变DOS标题#include<iostream>usingnamespacestd;voidmain(){system("title王万腾");system("pause");}打印出系统日期#include<iostream>usingnamespacestd;voidmain(){system("date");system("pause");}#include<iostream>usingnamespacestd;voidmain(){system("date/t");system("pause");}for_each的简单应用#include<iostream>#include<vector>#include<string>#include<algorithm>//特别注意：for_each()还是在algorithm头文件中定义的来usingnamespacestd;voidprint_i(intt){cout<<t<<ends;}intmain(){inta[]={1,2,3,4,5,6,7,8,9,10,11,12,13};vector<int>elements(a,a+13);for_each(elements.begin(),elements.end(),print_i);cout<<endl;system("pause");return0;}#include<iostream>#include<string>usingnamespacestd;intmain(){strings("WangWanteng");string::size_typelen2=s.size();cout<<"s.capacity():"<<s.capacity()<<ends<<"s.size():"<<len2<<endl;system("pause");return0;}总结：若s为一字符串，则s.size()==s.length(),s.capacity()总比s.size()或s.length()大4个字符string的substr()#include<iostream>#include<string>usingnamespacestd;intmain(){strings("WangWanteng");strings1("MaYu");s1=s.substr(4,3);cout<<s1<<endl;system("pause");return0;}上例：s.substr(4,3)是指从s串第（4+1）个字符开始往后数3个字符返回关于swap()的传说#include<iostream>#include<string>usingnamespacestd;intmain(){strings("Wangwanteng");strings1("王万腾");swap(s,s1);inta=1;intb=2;swap(a,b);cout<<a<<endl;cout<<s<<endl;system("pause");return0;}FunctionObjectsDefinitionAfunctionobjectisanobjecttowhichthefunctioncalloperatorcanbeapplied.Typically,itisaclassthatdefinesthefunctioncalloperator(operator()())as