Leap year

Write a function isLeapYear(year) that returns true if the year is a leap year and false if it is not.

• The parameter year is an integer from 1 to 9999.
• A year is a leap year if it divides by 4 with no remainder: 2024 is a leap year, 2023 is not.
• Exception: a year that divides by 100 is a leap year only if it also divides by 400. 1900 is not a leap year, 2000 is.
• Return a boolean: true or false, not the string 'true'.