string文字列の頭文字を大文字&配列の基本操作に変換

#include <iostream>//IO       
#include <string>//C++
#include <cstring>//C
#include <cstddef>//size_t
#include <vector>//      

using namespace std;//    

int main()
{
    string s("John_Tian 2013.9.3");
	cout<<s<<endl;//       

	string::iterator it=s.begin();
	 //convert first word in s to uppercase
	 while (it!=s.end()&&!isspace(*it))//isspace()       
	 {
		 *it=toupper(*it);//toupper          
		 ++it;
	 }
	 cout<<s<<endl;//            

	 const size_t array_size=5;//      ，   const size_t
	 int a[array_size]={0,1,2,3,4};

	 for (size_t ix=0;ix!=array_size;++ix)//  ++
	 {
		 cout<<a[ix]<<endl;
	 }
     cout<<"①"<<endl;
	 for (size_t iy=0;iy!=array_size;iy++)//  ++
	 {
		 cout<<a[iy]<<endl;
	 }
     cout<<"②"<<endl;
	 return 0;
}