Here is a TypeScript class that retrieves a model from localStorage:
export class LocalStorageHelper {
public static GetItemValue<T>(key: string): T {
let value: string = localStorage.getItem(key);
// if(typeof T == 'string') return value;
// return (Convert JSON.parse(value) To T)
}
}
I am interested in learning how to add comments within TypeScript code. Can someone provide guidance on this?
When TypeScript is compiled to JavaScript, there are no types present at runtime. This means that you cannot use typeof T in this context. To work around this limitation, you must somehow indicate the type of the object you intend to return. One approach would be to have separate methods for retrieving strings and parsing them into JSON.
export class LocalStorageHelper {
public static GetItemValueString(key: string): string {
let value: string = localStorage.getItem(key);
return value;
}
public static GetItemValue<T>(key: string): T {
let value: string = localStorage.getItem(key);
return JSON.parse(value) as T;
}
}
It's worth mentioning that even in strongly typed languages like Java, Scala, or C#, the compiler would not be able to determine whether you want to return a string or another type of object when using a generic type like T. T simply represents a placeholder for the actual return type.
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