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Table Of Contents
Clean Code with TypeScript
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Conditional types in TypeScript allow you to create types that adapt based on certain conditions. They are like if-else statements for types, helping you define dynamic and flexible type logic.
The basic structure of a conditional type is as follows:
T extends U ? X : Y;
This means if type T can be assigned to type U, then the result is type X. Otherwise, the result is type Y. Conditional types are powerful for creating dynamic type transformations and making your TypeScript code more type-safe and adaptable.
Now that we have defined the syntax, let's look under the hood to see how TypeScript evaluates these conditions and how you can use them to build intelligent type definitions.
At its core, a conditional type acts as a gatekeeper. It checks if a specific type relationship exists and returns one result if true, and another if false. We will start with a basic type check to see this syntax in action, and then explore how to use...