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Swift Program to Lookup enum by String value
An enumeration or enum is a user-defined data type which holds a set of related values. It is defined by using the enum keyword. It is also known as an enum case because it uses case keywords to declare values inside it. In Swift, we are allowed to create an enum by the string value.
Syntax
enum nameOfEnum: Type {
case value1
case value2
case value3
}
Let enumVariable = value
Here, nameOfEnum represents the name of the enum, value1, value2, etc are values defined in the enum and enumVariable is the variable of an enum type and can store only those values present inside the given enum.
Algorithm
Step 1 − Create an enum of string type.
Step 2 − Assign the values in the enum using the case statement.
Step 3 − Now create a function to get values from the enum.
Step 4 − Create a variable with a. value
Step 5 − Check if the value is present in the variable or not by calling the above function.
Step 6 − Display the output
Example 1
In the following Swift program, we will lookup an enum by the string value. So first we will create an enum of string type with 5 values. Then we create a variable of enum type and then assign the enum value to the variable using ProLanguages.Java and print the output.
import Foundation
import Glibc
enum ProLanguages: String {
case Swift
case Java
case Python
case Perl
case CSharp
}
// Create variable of enum
let resValue : ProLanguages
// Assigning value to the variable
resValue = ProLanguages.Java
print("Best programming Language is:", resValue)
Output
Best programming Language is: Java
Example 2
In the following Swift program, we will lookup enum by the string value. So first we will create an enum of string type with 6 values. Then create a function which takes an input string and tries to match it with the cases present in the given enum using rawValue initializer. If the match is found in the given enum, then it will return the value, otherwise return nil.
import Foundation
import Glibc
enum geomertyBox: String {
case Pencil
case Pen
case Sharpener
case Eraser
case Glue
}
func getElements(from str: String) -> geomertyBox? {
return geomertyBox(rawValue: str)
}
let inputItem = "Pen"
if let result = getElements(from: inputItem) {
print("Item found in the geomertyBox: \(result.rawValue)")
} else {
print("Try again!!")
}
Output
Item found in the geomertyBox: Pen
Conclusion
So this is how we can lookup an enum by the string value. In the enum, you can declare as much value as you want. Also, you can assign raw values to the enum values. You can also iterate through an enum using a for-in loop. It allows you to work with values in a type-safe way. It is generally used when the developer has multiple options to encode.
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