How to use custom mapping In Typescript

Using the keyof and typeof operators together

In this approach, we will define an enum initialized with string values and then map through each item to compare them with a string and return the matching enum value to convert the string into an enum.

Example: The below example will explain how you can convert a string into an enum using custom mapping.

Javascript

enum GFG {
    name = "w3wiki",
    desc = "A Computer Science portal."
}

// Function to convert string into enum
function convertStrToEnum(convertingStr: string):
    GFG | string {
    switch (convertingStr) {
        case "w3wiki":
            return GFG.name;
        case "A Computer Science portal.":
            return GFG.desc;
        default:
            return `Pass either "${GFG.name}" or "${GFG.desc}" 
            as testing string to the function`;
    }
}

console.log(convertStrToEnum("w3wiki"));
console.log(convertStrToEnum("TypeScript"));
console.log(convertStrToEnum("A Computer Science portal."));

Output:

w3wiki
Pass either "w3wiki" or "A Computer Science portal." as testing string to the function
A Computer Science portal.

How to Convert a String to enum in TypeScript?

In TypeScript, an enum is a type of class that is mainly used to store the constant variables with numerical and string-type values. In this article, we will learn, how we can convert a string into an enum using TypeScript.

These are the two approaches that can be used to solve it: