C# Switch Char, Test Chars With Cases

Use the switch statement on a char variable. Lowercase and uppercase chars can be handled the same way with a switch.
Switch can handle char cases. Because a char is a value, switch can use jump tables to test chars. You can take a char value and get a full string version of it—using the switch statement on characters.CharSwitch
An example. There are several ways of looking up characters and getting equivalent values for them. Some options include if conditional statements, switch statements, and lookup tables.

Info: This code takes an arbitrary char value, which is returned from the char.Parse method, and passes the char as an argument to the SwitchChar method.

Note: The SwitchChar method uses the switch control statement. It uses the switch statement on chars.

SwitchChar: This method tests if the char is equal to known character value, or if it is not. The default case deals with all other cases.

Cases: The 3 cases S, T, and U in the switch are stacked on other cases. This is a way to normalize data and treat "s" and "S" equivalently.

C# program that switches on char using System; class Program { static void Main() { char input1 = char.Parse("s"); string value1 = SwitchChar(input1); char input2 = char.Parse("c"); string value2 = SwitchChar(input2); Console.WriteLine(value1); Console.WriteLine(value2); Console.WriteLine(SwitchChar('T')); } static string SwitchChar(char input) { switch (input) { case 'a': { return "Area"; } case 'b': { return "Box"; } case 'c': { return "Cat"; } case 'S': case 's': { return "Spot"; } case 'T': case 't': { return "Test"; } case 'U': case 'u': { return "Under"; } default: { return "Deal"; } } } } Output Spot Cat Test
Internally, you will find that char switches result in the jump table instruction, such as "switch (L_002e, L_0034, L_003a)". Jump tables are a way to achieve much faster lookup by using multiplication and addition instructions.

So: The value of the switch value is used to find the correct case. This is faster than using if-statements in common situations.

Switch Enum
Summary. You can switch on the character type in the C# language. This is an efficient and terse way to find the values of individual characters. In the language, you cannot switch on character ranges, but must stack the cases.

Review: The switch statement on char is compiled into an efficient jump table, often providing faster lookup than if-statements.

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