Can a variable in Typescript be defined to accept any value as long as it follows a specific format?

For instance, I am searching for a way to represent any value that consists of two strings separated by an underscore "_".
I attempted something along the lines of: 

let key:string = string1 + "_" + string2;

Upon entering this code, I quickly realized that it wouldn't actually work as intended...

I am aware that in Typescript, interfaces can be used to define permitted keys and values for objects. But how about for other scenarios?

Since I am new to this, I apologize if my approach is completely off track.

javascriptstringtypescripttypes

Answer №1

Currently, TypeScript does not support regex validated string types. However, there is an ongoing discussion on GitHub regarding the implementation of this feature. You can show your support by voting for it or contributing to the suggestion :)

https://github.com/Microsoft/TypeScript/issues/6579

If you need to validate if a string matches a specific pattern (such as two strings connected with "_") at runtime, you can use regex matching like this:

function verifyStringPattern(inputString: string) {
    const regex = /.+_.+/g;
    return inputString && inputString.match(regex) !== null;
}

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