C# defines global variables

  • The following is an example of writing a global variable. Note that the global variable needs to be static

    • public static string[] coffees = new string[] { "Espresso"."Blended coffee"."Reroasted coffee" };
public static int[] coffeePrice = new int[] { 25.30.20 };
public static string[] others = new string[] { "Mocha"."Milk bubble"."Milk" };
public static int[] otherPrice = new int[] { 10.8.6 };
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An array of

  • Define an array array

    • Indefinite length

      • The new operator can be omitted if an initial setting is provided
      • Int [] Numbers = new int [] {1, 2, 3, 4, 5};
      • Int [] Numbers = {1, 2, 3, 4, 5};

    • Fixed-length writing

      • Int [] Numbers = new int [3] {1, 2, 3};

    • Multidimensional array definition

      • Indeterminate multidimensional array
      • Int [and] Numbers = new int [and] {{1, 2, 3}, {1, 2, 3}, {1, 2, 3}};
      • Fixed-length multidimensional array
      • Int [and] Numbers = new int [3, 3] {{1, 2, 3}, {1, 2, 3}, {1, 2, 3}};

    • The initialization method is used

      • // If the value is assigned first, the value is 0, and the value is 0
int [] numbers=new int[3];
// This definition method assignment notation
numbers[0] =1;
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  • Defining a string array

    • Indefinite length
      • The new operator can be omitted if an initial setting is provided
      • string[] str={"A","B","C"};
      • string[] str=new string[]{"A","B","C"};
    • Fixed-length writing
      • string[] str=new string[3]{"A","B","C"};

  • Defining an array of objects

    • Object[] obj = new Object[] { 1, 2, 3, 4, 5 };

C# gets the variable type

  • An example of getting a variable type is as follows:

    • // The first display method
System.Type t=123.GetType();
Console.WriteLine(t);
// The second method
Console.WriteLine(123.GetType());
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Try to transform

  • TryParse can be used to solve the embarrassing problem that many applications will crash due to unsuccessful conversions.
    • Example: Try a string variablestrTry converting to a numeric variablenumbers.numbersandstrAll need to be declared before calling;
    • int.TryParse(str,out numbers);
      • Note that it has a return value, its return value is a Boolean value, true on success, false otherwise;numberIf the conversion succeeds, the corresponding digit is 0; if the conversion fails, the corresponding digit is 0.
    • If you want to learn more about TryParse, I have attached a link to TryParse in Depth

The pause

  • Console.ReadLine(); When the program runs to this point, the program stops automatically.

This note is only when I am writing the coffee shop decorator mode, I am not proficient in the part of the code, attached has been uploaded to GitHub decorator mode code:

Simple coffee shop billing function completed by console application