Как мне выразить даты в TypeScript? Даты не являются типом TypeScript, поэтому я использую any или object? Похоже, что был бы "правильный" способ сделать:
let myDate: any = new Date();
Я не мог найти много в Google, несмотря на то, что это был такой простой вопрос.
Ответ супер прост, тип Date:
const d: Date = new Date(); // but the type can also be inferred from "new Date()" already
Это то же самое, что и с любым другим экземпляром объекта:)
Любой класс или интерфейс может использоваться как тип в TypeScript.
const date = new Date();
уже знает о определении типа date как date - это внутренний объект TypeScript, на который ссылается интерфейс DateConstructor.
И для используемого вами конструктора он определяется как:
interface DateConstructor {
new(): Date;
...
}
Чтобы сделать его более явным, вы можете использовать:
const date: Date = new Date();
Возможно, вам не нужны определения типов, но date отправляется за моим примером из библиотеки ES6, а в моем tsconfig.json я определил:
"compilerOptions": {
"target": "ES6",
"lib": [
"es6",
"dom"
],
Вы можете адаптировать эти параметры, чтобы настроить желаемую версию JavaScript.
Дата, кстати, является интерфейсом от lib.es6.d.ts:
/** Enables basic storage and retrieval of dates and times. */
interface Date {
/** Returns a string representation of a date. The format of the string depends on the locale. */
toString(): string;
/** Returns a date as a string value. */
toDateString(): string;
/** Returns a time as a string value. */
toTimeString(): string;
/** Returns a value as a string value appropriate to the host environment current locale. */
toLocaleString(): string;
/** Returns a date as a string value appropriate to the host environment current locale. */
toLocaleDateString(): string;
/** Returns a time as a string value appropriate to the host environment current locale. */
toLocaleTimeString(): string;
/** Returns the stored time value in milliseconds since midnight, January 1, 1970 UTC. */
valueOf(): number;
/** Gets the time value in milliseconds. */
getTime(): number;
/** Gets the year, using local time. */
getFullYear(): number;
/** Gets the year using Universal Coordinated Time (UTC). */
getUTCFullYear(): number;
/** Gets the month, using local time. */
getMonth(): number;
/** Gets the month of a Date object using Universal Coordinated Time (UTC). */
getUTCMonth(): number;
/** Gets the day-of-the-month, using local time. */
getDate(): number;
/** Gets the day-of-the-month, using Universal Coordinated Time (UTC). */
getUTCDate(): number;
/** Gets the day of the week, using local time. */
getDay(): number;
/** Gets the day of the week using Universal Coordinated Time (UTC). */
getUTCDay(): number;
/** Gets the hours in a date, using local time. */
getHours(): number;
/** Gets the hours value in a Date object using Universal Coordinated Time (UTC). */
getUTCHours(): number;
/** Gets the minutes of a Date object, using local time. */
getMinutes(): number;
/** Gets the minutes of a Date object using Universal Coordinated Time (UTC). */
getUTCMinutes(): number;
/** Gets the seconds of a Date object, using local time. */
getSeconds(): number;
/** Gets the seconds of a Date object using Universal Coordinated Time (UTC). */
getUTCSeconds(): number;
/** Gets the milliseconds of a Date, using local time. */
getMilliseconds(): number;
/** Gets the milliseconds of a Date object using Universal Coordinated Time (UTC). */
getUTCMilliseconds(): number;
/** Gets the difference in minutes between the time on the local computer and Universal Coordinated Time (UTC). */
getTimezoneOffset(): number;
/**
* Sets the date and time value in the Date object.
* @param time A numeric value representing the number of elapsed milliseconds since midnight, January 1, 1970 GMT.
*/
setTime(time: number): number;
/**
* Sets the milliseconds value in the Date object using local time.
* @param ms A numeric value equal to the millisecond value.
*/
setMilliseconds(ms: number): number;
/**
* Sets the milliseconds value in the Date object using Universal Coordinated Time (UTC).
* @param ms A numeric value equal to the millisecond value.
*/
setUTCMilliseconds(ms: number): number;
/**
* Sets the seconds value in the Date object using local time.
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setSeconds(sec: number, ms?: number): number;
/**
* Sets the seconds value in the Date object using Universal Coordinated Time (UTC).
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setUTCSeconds(sec: number, ms?: number): number;
/**
* Sets the minutes value in the Date object using local time.
* @param min A numeric value equal to the minutes value.
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setMinutes(min: number, sec?: number, ms?: number): number;
/**
* Sets the minutes value in the Date object using Universal Coordinated Time (UTC).
* @param min A numeric value equal to the minutes value.
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setUTCMinutes(min: number, sec?: number, ms?: number): number;
/**
* Sets the hour value in the Date object using local time.
* @param hours A numeric value equal to the hours value.
* @param min A numeric value equal to the minutes value.
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setHours(hours: number, min?: number, sec?: number, ms?: number): number;
/**
* Sets the hours value in the Date object using Universal Coordinated Time (UTC).
* @param hours A numeric value equal to the hours value.
* @param min A numeric value equal to the minutes value.
* @param sec A numeric value equal to the seconds value.
* @param ms A numeric value equal to the milliseconds value.
*/
setUTCHours(hours: number, min?: number, sec?: number, ms?: number): number;
/**
* Sets the numeric day-of-the-month value of the Date object using local time.
* @param date A numeric value equal to the day of the month.
*/
setDate(date: number): number;
/**
* Sets the numeric day of the month in the Date object using Universal Coordinated Time (UTC).
* @param date A numeric value equal to the day of the month.
*/
setUTCDate(date: number): number;
/**
* Sets the month value in the Date object using local time.
* @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
* @param date A numeric value representing the day of the month. If this value is not supplied, the value from a call to the getDate method is used.
*/
setMonth(month: number, date?: number): number;
/**
* Sets the month value in the Date object using Universal Coordinated Time (UTC).
* @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
* @param date A numeric value representing the day of the month. If it is not supplied, the value from a call to the getUTCDate method is used.
*/
setUTCMonth(month: number, date?: number): number;
/**
* Sets the year of the Date object using local time.
* @param year A numeric value for the year.
* @param month A zero-based numeric value for the month (0 for January, 11 for December). Must be specified if numDate is specified.
* @param date A numeric value equal for the day of the month.
*/
setFullYear(year: number, month?: number, date?: number): number;
/**
* Sets the year value in the Date object using Universal Coordinated Time (UTC).
* @param year A numeric value equal to the year.
* @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively. Must be supplied if numDate is supplied.
* @param date A numeric value equal to the day of the month.
*/
setUTCFullYear(year: number, month?: number, date?: number): number;
/** Returns a date converted to a string using Universal Coordinated Time (UTC). */
toUTCString(): string;
/** Returns a date as a string value in ISO format. */
toISOString(): string;
/** Used by the JSON.stringify method to enable the transformation of an object data for JavaScript Object Notation (JSON) serialization. */
toJSON(key?: any): string;
}
Typescript распознает интерфейс Date прямо из коробки - так же, как если бы вы использовали число, строку или пользовательский тип. Так что просто используйте:
myDate : Date;