C# provides, by default a parameterless constructor. If I write a constructor that takes

C# provides, by default a parameterless constructor. If I write a constructor that takes a string as a parameter, but want to keep the parameterless constructor. How many constructors should I write？

(C#提供默认构造函数(不带参数),如果我写了一个带有一个string类型参数的构造函数,但是又想保留不带参数的构造函数,那么我需要写多少个构造函数)

请帮忙给出正确答案和分析，谢谢！