'变量已赋值，但从未使用过它的值' & '该名称在当前上下文中不存在'

Question

I've looked into this but still can't seem to figure it out.

I thought I've used the variable, but I'm guessing I haven't. I'm very new to C#, coming over from Python, so it could be a language/formatting difference I haven't ironed out yet?

I'm getting "The name 'number' does not exist in the current context" and "The variable 'number_wording' is assigned but its value is never used"

using System;

public class HelloWorld
{
    public static void Main(string[] args)
    {
    number = 1;

    if (number == 1)
    {
        string number_wording = "the number is 1";
    }
    else
    {
        string number_wording = "the number is not 1";
    }
    Console.WriteLine("{0}", number_wording);

Answer 1

You must declare every variable that you use in C# and you must declare it in a scope that can be seen by everything that uses it:

int number = 1;

string number_wording = "the number is not 1";

if (number == 1)
{
    number_wording = "the number is 1";
}

Console.WriteLine("{0}", number_wording);

---

Perhaps this is slightly nicer:

int number = 1;

Console.WriteLine("the number is {0}", number == 1 ? "1" : "not 1");

---

Or even this:

int number = 1;
string number_wording = $"the number is {(number == 1 ? "1" : "not 1")}";
Console.WriteLine(number_wording);