将字符串使用递归和循环逆序输出

使用递归实现字符串逆序输出：

def reverse_string_recursive(s):
    if len(s) == 0:
        return s
    else:
        return reverse_string_recursive(s[1:]) + s[0]

s = "Hello, world!"
print(reverse_string_recursive(s))

使用循环实现字符串逆序输出：

def reverse_string_loop(s):
    result = ""
    for i in range(len(s)-1, -1, -1):
        result += s[i]
    return result

s = "Hello, world!"
print(reverse_string_loop(s))