104 lines
2.8 KiB
Markdown
104 lines
2.8 KiB
Markdown
---
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title: Switch Case
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---
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# Switch Case
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Switch is a selection statement that chooses a switch case section depending on the value matched with the expression/value being evaluated.<sup>1</sup> If none of the case statements match the value of the switched variable, the default path is chosen. The switch statement is like a set of `if statements`. We exit from the switch by `break`.
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## Example
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```
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public enum Colors { Red, Blue, Green, Orange }
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Colors myColor;
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... myColor is set to one of the enum values ...
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switch(myColor){
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case Colors.Red:
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Console.WriteLine("How you like them apples?");
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break;
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case Colors.Blue:
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Console.WriteLine("Ice Ice Baby...");
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break;
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case Colors.Green:
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Console.WriteLine("Fore!");
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break;
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default:
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Console.WriteLine("I have a hard time when I try to rhyme.");
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}
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```
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## Output
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```
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If myColor is Colors.Red:
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> How you like them apples?
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If myColor is Colors.Blue:
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> Ice Ice Baby...
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If myColor is Colors.Green:
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> Fore!
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If myColor is Colors.Orange:
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> I have a hard time when I try to rhyme.
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```
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## Fallthrough
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It is also possible to use multiple statements produce the same outcome, by letting the cases 'fallthrough', like so:
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```
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switch(myColor) {
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case Colors.Red:
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case Colors.Blue:
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//Code
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break;
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...
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}
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```
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This will execute the same lines of code if myColor is either Red or Blue.
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## When clause
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Starting with C# 7.0 you can use `when` clause to specify additional condition that must be satisfied. When clause is optional and is used right after specific case.
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```csharp
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Dog dog = new Dog
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{
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Name = "Charlie",
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Breed = "Affenpinscher",
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Age = 3
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};
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switch (dog)
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{
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case Dog d when d.Breed == "Affenpinscher" && d.Age >= 6:
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Console.WriteLine($"{dog.Name} is considered a senior dog.");
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break;
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case Dog d when d.Breed == "Affenpinscher" && d.Age >= 2:
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Console.WriteLine($"{dog.Name} is considered an adult dog.");
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break;
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case Dog d when d.Breed == "Affenpinscher":
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Console.WriteLine($"{dog.Name} is considered a puppy.");
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break;
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case Dog d when d.Breed == "Chihuahua" && d.Age >= 4:
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Console.WriteLine($"{dog.Name} is considered a senior dog.");
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break;
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case Dog d when d.Breed == "Chihuahua" && d.Age >= 2:
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Console.WriteLine($"{dog.Name} is considered an adult dog.");
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break;
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case Dog d when d.Breed == "Chihuahua":
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Console.WriteLine($"{dog.Name} is considered a puppy.");
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break;
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default:
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Console.WriteLine($"We have no information according {dog.Breed} breed.");
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break;
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}
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```
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As you see in the above example after `when` keyword you should specify logical condition (an instruction that returns bool value).
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### Sources:
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- 1 https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/switch
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