闭区间运算符：a...b

for i in 1...10 

{

print("\(i)");

}

半闭区间运算符：a..<b

for m in 1..<5 {

print("\(m)");

}

倒序循环

for n in (0...10).reversed() {

print("倒序循环=========\(n)");

}