Convert string array to different types and values using generics in TypeScript
When working with TypeScript, you may come across situations where you need to convert a string array into different types and values. This can be a common requirement when dealing with data from external sources or when manipulating user input. In this blog post, we will explore how to achieve this using generics in TypeScript.
Using a generic function
The first approach to convert a string array to different types and values is by using a generic function. This allows us to define the desired output type as a parameter to the function. Here’s an example:
function convertArray(array: string[]): T[] {
return array.map((item) => JSON.parse(item) as T);
}
// Usage
const stringArray = ['1', '2', '3'];
const numberArray = convertArray(stringArray);
const booleanArray = convertArray(stringArray);
console.log(numberArray); // [1, 2, 3]
console.log(booleanArray); // [true, true, true]
In the above code snippet, we define a generic function called convertArray that takes an array of strings as input. Inside the function, we use the map method to iterate over each item in the array and parse it using JSON.parse. By using the as T syntax, we can cast the parsed value to the desired type specified by the generic parameter.
By calling convertArray, we can convert the string array into a number array. Similarly, convertArray converts the string array into a boolean array.
Using type assertions
Another way to convert a string array to different types and values is by using type assertions. This approach allows us to manually specify the desired type for each item in the array. Here’s an example:
const stringArray = ['1', '2', '3'];
const numberArray = stringArray.map((item) => Number(item));
const booleanArray = stringArray.map((item) => item === 'true');
console.log(numberArray); // [1, 2, 3]
console.log(booleanArray); // [true, true, true]
In the above code snippet, we use the map method to iterate over each item in the string array. For the numberArray, we use the Number function to convert each item into a number. For the booleanArray, we compare each item with the string ‘true’ to convert it into a boolean value.
Conclusion
Converting a string array to different types and values in TypeScript can be achieved using generics or type assertions. The choice between these approaches depends on the specific requirements of your project. Generics provide a more flexible and reusable solution, while type assertions offer more control over the conversion process.
By leveraging the power of TypeScript, you can easily convert string arrays into different types and values, making your code more robust and efficient.
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