In TypeScript, you can use an array to represent a closed list of strings by specifying the valid string values as elements of the array. Here's how you can create and use such an array:
```typescript
const validColors: string[] = ["red", "green", "blue"];
function getColorName(color: string): string {
if (validColors.includes(color)) {
return color;
} else {
throw new Error("Invalid color");
}
}
// Example usage:
try {
const selectedColor = "red";
const validColor = getColorName(selectedColor);
console.log(`Selected color: ${validColor}`);
} catch (error) {
console.error(error.message);
}
```
In this example:
1. `validColors` is an array that contains a list of valid color strings: "red", "green", and "blue".
2. The `getColorName` function takes a string argument, checks if it exists in the `validColors` array using `includes`, and returns the same string if it's valid. If the input is not in the valid list, it throws an error.
3. In the example usage, we call `getColorName` with a valid color ("red") and then handle the result. If an invalid color is provided, it throws an error.
By using an array in this way, you can create a closed list of valid string values, ensuring that only the specified strings are accepted, and any other values are considered invalid.