运用for 语句来计算 从1加到10的用法 C++

计算方式：
1+2+3+4+5+6+7+8+9+10 等于什么？

用for 语句来设计
for 语法3个组成：
1.一个初始化（init-statement）：int val = 1
2.一个循环条件（condition）：val <= 10
3.一个表达式 （expression）：++val
ex：
for( int val = 1; val <= 10; ++val )

#include <iostream>

int main(int argc, const char * argv[]) {
    int sum=0; //初始化sum
    //从1加到10
    for( int val = 1; val <= 10; ++val )
    sum +=val; //与 sum=sum+val 相同
    std::cout << "sum of 1 to 10 inclusive is " << sum << std:: endl;
    return 0;
    
}

sum of 1 to 10 inclusive is 55
Program ended with exit code: 0

Extend
从50 加到100

#include <iostream>
using namespace std;
int main(int argc, const char * argv[]) {
    int sum =0 ;
    //从50加到100
    for (int i=50; i<=100;++i)
    sum += i;
    cout << " Sum of 50 to 100 inclusive is " << sum << endl;
    return 0;
}

结果

 Sum of 50 to 100 inclusive is 3825
Program ended with exit code: 0