Question

there are many ways to cast/convert object to another by what the difference between those and if there is no difference why there are so many ways to achieve one thing? Isn’t that damage to language?

let’s say object obj to string.

obj.ToString()
obj as string
(string)obj
Convert.ToString(obj)

Answer 1

You are doing different things here:

• obj.ToString() – this is a call to the ToString() method of the object. The object returns a string as it was programmed to.
• obj as string – this is an attempt to convert the object to a string, which may or may not fail (if it fails, the result is null), no exception will be thrown.
• (string)obj – this is an explicit cast of obj to the type string, you are telling the compiler that obj is a string. If obj is not a string type, you will get a cast exception.
• Convert.ToString(obj) – This is an explicit call to the Convert class to return a string representation of obj.

There are these many different ways to get a string from an object because each one is different and have subtle differences. Yes, in many cases the returned string will be the same, but this is not guaranteed.