JAVASCRIPT

leap year condition in javascript

//Easiest Leap-year condition
function isLeapyear(year){
    if(year%4==0  ||  year%400==0   &&   year%1000!=0){
        return true;
    }
    else{
        return false;
    }
}


const my_year = isLeapyear(1999);  //Tip: 2000 is a leap year.

console.log('My year is', my_year );

javascript leap year

function isLeapYear(year){
	if(year % 400 === 0 && year % 4 === 0){
      return true
    } else {
      return false
    }
}

Leap year function javascript

function isLeapYear(year) {
    if (year % 4 == 0) {
        console.log("leap year")
    } else {
        console.log("Not a leap year")
    }
}
var myYear = 2020;
isLeapYear(myYear)
// Output:leap year

get days in leap year javascript

You can find the number of days using the simple leap year algorithem:
In the Gregorian calendar three criteria must be taken into account to identify 
leap years: The year can be evenly divided by 4; If the year can be evenly 
divided by 100, it is NOT a leap year, unless; The year is also evenly divisible
by 400. Then it is a leap year.
function daysInYear(year) {
    return ((year % 4 === 0 && year % 100 > 0) || year %400 == 0) ? 366 : 365;
}
console.log(daysInYear(2016));
console.log(daysInYear(2017));

javascript Program to check if a given year is leap year

<script>
 
// Javascript program to check
// for a leap year
 
    function checkYear( year) {
        // If a year is multiple of 400,
        // then it is a leap year
        if (year % 400 == 0)
            return true;
 
        // Else If a year is multiple of 100,
        // then it is not a leap year
        if (year % 100 == 0)
            return false;
 
        // Else If a year is multiple of 4,
        // then it is a leap year
        if (year % 4 == 0)
            return true;
        return false;
    }
 
    // Driver method
      
        let year = 2000;
        document.write(checkYear(2000) ? "Leap Year" : "Not a Leap Year");
 
 
// This code is contributed by shikhasingrajput
 
</script>