#include<iostream>

int main(){

        int sum=,val=;

 //只要val小于10（condition）则一直执行执行while循环内的语句

        while(val<=){

             sum+=val;

             ++val;//val 加1 add 1 to val   等于val=val +1;

        }

        std::cout<<"sum of 1 to 10 is "<<sum<<std::endl;

        return ;

}           

//write a program that uses a while to sum the numbers from 50 to 100

#include<iostream>

using namespace std;

int main(){

        int sum=,val=;

        while(val<=){

        sum+=val;

        ++val;

        }

        cout<<"sum of 50 to 100 is "<<sum<<endl;

        return ;

}

/*write a program that prompts the user for two intergers,print each number in the range specified by those two interger*/

#include<iostream>

using namespace std;

int main(){

        int val1=,val2=,tmp=;

        cout<<"Enter the first number: ";

        cin>>val1;

        cout<<"Enter the second number:";

        cin>>val2;

        if(val1>val2){

        tmp=val1;

        val1=val2;

        val2=val1;

        }

        while(val1<=val2){

                tmp=val1;

                ++val1;

                cout<<tmp<<endl;

        }

        return ;

}