What is the usage of tostring in c#?

In C#, the ToString() method is a method of the Object class, used to convert the value of an object into a string representation. This method can be called by all C# objects, as all C# classes inherit from the Object class.

The main purpose of the ToString() method is to easily convert an object to a string for display or output. By default, ToString() returns the fully qualified name of the object. However, it can be overridden to return a custom string representation of the specific object.

Here is an example of how to use the ToString() method:

1. Utilize the default ToString() method.

int number = 10;
string numberString = number.ToString();
Console.WriteLine(numberString); // 输出："10"

1. Rewrite the ToString() method.

class Person
{
    public string Name { get; set; }
    public int Age { get; set; }

    public override string ToString()
    {
        return $"Person: {Name}, Age: {Age}";
    }
}

Person person = new Person { Name = "John", Age = 25 };
string personString = person.ToString();
Console.WriteLine(personString); // 输出："Person: John, Age: 25"

1. 手动调用ToString()方法：

DateTime currentDate = DateTime.Now;
string dateString = currentDate.ToString("yyyy-MM-dd");
Console.WriteLine(dateString); // 输出当前日期的字符串表示形式，例如："2021-01-01"

In conclusion, the ToString() method is a common method used to convert an object into a string, which is very useful when you need to display the value of an object as a string.