What are type guards in TypeScript and how can I use them in React?

What are type guards in TypeScript and how can I use them in React?

Type guards are TypeScript features that allow you to narrow down the type of a variable within a conditional block. In React, they help ensure that your components receive the correct props.

Can you give me an example of a type guard in a React component?

Sure! Here's a simple example:

function isString(value: any): value is string {
    return typeof value === 'string';
}

const MyComponent: React.FC<{ data: string | number }> = ({ data }) => {
    if (isString(data)) {
        return <div>{data}</div>;
    }
    return <div>Number: {data}</div>;
};

How do type guards improve type safety in my React app?

Type guards enhance type safety by allowing you to define specific conditions under which a variable can be treated as a certain type, reducing runtime errors and improving code clarity.

Are there any built-in type guards in TypeScript?

Yes, TypeScript has built-in type guards like typeof and instanceof that you can use to check types at runtime.