# 2777. Date Range Generator

## Description

Given a start date start, an end date end, and a positive integer step, return a generator object that yields dates in the range from start to end inclusive. All dates are in the string format YYYY-MM-DD. The value of step indicates the number of days between consecutive yielded values.

Example 1:

Input: start = "2023-04-01", end = "2023-04-04", step = 1
Output: ["2023-04-01","2023-04-02","2023-04-03","2023-04-04"]
Explanation:
const g = dateRangeGenerator(start, end, step);
g.next().value // '2023-04-01'
g.next().value // '2023-04-02'
g.next().value // '2023-04-03'
g.next().value // '2023-04-04'

Example 2:

Input: start = "2023-04-10", end = "2023-04-20", step = 3
Output: ["2023-04-10","2023-04-13","2023-04-16","2023-04-19"]
Explanation:
const g = dateRangeGenerator(start, end, step);
g.next().value // '2023-04-10'
g.next().value // '2023-04-13'
g.next().value // '2023-04-16'
g.next().value // '2023-04-19'

Example 3:

Input: start = "2023-04-10", end = "2023-04-10", step = 1
Output: ["2023-04-10"]
Explanation:
const g = dateRangeGenerator(start, end, step);
g.next().value // '2023-04-10'


Constraints:

• new Date(start) <= new Date(end)
• 0 <= The difference in days between the start date and the end date <= 1000
• 1 <= step <= 100

## Solutions

• function* dateRangeGenerator(start: string, end: string, step: number): Generator<string> {
const startDate = new Date(start);
const endDate = new Date(end);
let currentDate = startDate;
while (currentDate <= endDate) {
yield currentDate.toISOString().slice(0, 10);
currentDate.setDate(currentDate.getDate() + step);
}
}

/**
* const g = dateRangeGenerator('2023-04-01', '2023-04-04', 1);
* g.next().value; // '2023-04-01'
* g.next().value; // '2023-04-02'
* g.next().value; // '2023-04-03'
* g.next().value; // '2023-04-04'
* g.next().done; // true
*/