★★★for循环语句循环次数的问题★★★

#include <iostream.h>
void main()
{
//显示1，2...10
for(int i=1; i<=10; i++)
cout << i << " " ;
cout << endl;

//显示10，9，8...1
for(int j=10; j>=1; j--)
cout << j << " ";
cout << endl;

//显示1，3，5...9
for(int k=1; k<=10; k=k+2)
cout << k << " ";
cout << endl;

//显示ABC...Z
for(char c='A'; c<='Z'; c++)
cout << c << " ";
cout << endl;

//显示0，0.1，0.2...1.0
for(float x=0; x<=1; x=x+0.1) //为什么输出结果里没有1？只有0.1到0.9
cout << x << " ";
cout << endl;

//显示0，0.1，0.2...1.0
for(float x1=0; x1<=1.0+0.1/2; x1=x1+0.1) //为什么这个语句就可以输出0，0.1，0.2...1.0
cout << x1 << " ";
cout << endl;

//计算s=1+2+3...+100
int s=0;
for(int n=1; n<=100; n++)
s=s+n;
cout << "s=" << s << endl;
}