NativeScript/application-settings/application-settings.d.ts

/**
 * Allows you to save and restore any kind of information related to your application.
 */
declare module "application-settings" {
   /**
    * Checks whether such a key exists.
    * @param key The key to check for.
    */
    export function hasKey(key: string): boolean;

   /**
    * Gets a value (if existing) for a key as a Boolean Object. A default value can be provided in case there is no existing value.
    * @param key The key to check for.
    * @param defaultValue An optional value to be returned in case there is no existing value.
    */
    export function getBoolean(key: string, defaultValue?: boolean): boolean;

   /**
    * Gets a value (if existing) for a key as a String Object. A default value can be provided in case there is no existing value.
    * @param key The key to check for.
    * @param defaultValue An optional value to be returned in case there is no existing value.
    */
    export function getString(key: string, defaultValue?: string): string;

   /**
    * Gets a value (if existing) for a key as a Number Object. A default value can be provided in case there is no existing value.
    * @param key The key to check for.
    * @param defaultValue An optional value to be returned in case there is no existing value.
    */
    export function getNumber(key: string, defaultValue?: number): number;

   /**
    * Sets a Boolean Object for a key.
    * @param key The key.
    * @param value The value.
    */
    export function setBoolean(key: string, value: boolean): void;

   /**
    * Sets a String Object for a key.
    * @param key The key.
    * @param value The value.
    */
    export function setString(key: string, value: string): void;

   /**
    * Sets a Number Object for a key.
    * @param key The key.
    * @param value The value.
    */
    export function setNumber(key: string, value: number): void;

   /**
    * Removes a value (if existing) for a key.
    * @param key The key to check for.
    */
    export function remove(key: string): void;

    /**
     * Removes all values.
     */
    export function clear(): void;
}