将整数转换为字符串“” +1和1.ToString（）的区别

Question

What is the difference when I convert integer to string like this way:

string str = "" + 1;

And

string str =1.ToString();

Answer 1

The first method is equivalent to string str = "" + 1.ToString(); and uses 2 intermediate strings before producing the result. That amounts to 3 strings total: an empty string, "1", and the result of the concatenation, which is also "1".

The second method doesn't use any intermediate string. It's also more readable and clearly expresses your intent (which is to convert the integer into a string).

Answer 2

With ToString() you assign a return value of the method. By using "" + 1 the ToString() method is called by the CLR.

See Automatic .ToString()?

Answer 3

int.ToString() is the tool for converting an integer into a string.

However, the C# allows you not to call this method when concatenating strings via plus operator , and the framework calls .ToString() instead of you.