A C#'s little problem

Question

Hello everyone,

I need your help for a little problem with my program.
this is the code:

"
int x = 10;
Console.WriteLine("the starting number is : " + x);

x++;
Console.WriteLine("the starting number '" + x + "' + 1: " + x);

int x7 = x;
x7--;
Console.WriteLine("the starting number '" + x + "' - 1: " + x7);

"

The problem is that on output, this is the result:

"
the starting number is: 10
the starting number '11' + 1: 11
the starting number '11' - 1, fa: 10
"

if i create a variable where copy the x's value, the program works, if i don't do it, it not works. I know why it happens, but i want ask you how i can solve it without use a new variable for do "x++" or "x--". I want use a "still" variable that can't modify the value, and use operator on it for my output.. I need to do, for example, "x = x+5" only for my output, but the x's value need still the same of the start code.

PS: Sorry for that, i'm noobie :D and also, sorry for my bad english, i hope that it was understandable :(

Thanks from Italy :)

Answer 1

You can declare constants, which can never be changed, using the const keyword.
In you printout, you can print the result of expressions that use a variable or constant, but don't change it. Like:
Console.WriteLine(x + 1);

x++ is tricky because it also changes the value of the original variable. You cannot use it with const!

There is also a technique called string interpolation, which lets you combine text and variables or expressions into a single string. Try this:

const int x = 10;
Console.WriteLine(quot;The number is {x}");
Console.WriteLine(quot;One less: {x-1}");
Console.WriteLine(quot;Twice: {x*2}");
Console.WriteLine(quot;The number is {x}");

Answer 2

// Try it

Console.WriteLine(quot;the starting number {x} + 1: {++x}");

Console.WriteLine(quot;the starting number {x} - 1: {--x}");

Answer 3

Thank you!