## Input year-month-day, how many days is the output?

- Ideas:
- If you enter 2018-11-11, how many days is the calculation in this year?
- Use the number of days in the previous 10 months and add 11, the number of days in the 11th month.

- question:

- This involves the number of days in February in a leap year.
- In a normal year, February has 28 days, and in a leap year, it has 29 days.

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Code logic:

- If the input is January, you can directly output the number of days, which is the number of days in the year.
- We first give the number of days in February 28 days, if it is a leap year, let it add one more day.
- If it is January and February, it doesn't matter whether it is a leap year or a normal year, because it will give the number of days; so from the conditions of March, to judge whether it is a leap year or a normal year, if it is a leap year, add 1 day to the total number of days.

<script> /* Enter the year, month and day, and judge the day of the year*/ var aryDays = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]; function isLeapYear(year) { if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0) { return true; // is a leap year } else { return false; // is a normal year } } function getDate (year, month, days) { if(month == 1) //If the input is January, directly output the number of days { return days; } for(var i = 0; i < month - 1; i++) //If the input is not January, use the sum of the previous (month - 1) month and add the number of days { days += aryDays[i]; } if(isLeapYear(year) && month > 2) //Determine whether it is a normal year or a leap year, and the number of days in February is different { days++; } return days; } console.log(getDate(2000, 3, 2)); </script>