Question

How to check if year is leap year in JavaScript

Answer 1

function isLeapYear(year) {
  	return (year % 4 === 0 && year % 100 !==0 || year % 400 === 0);
}

console.log(isLeapYear(2020)); 

console.log(isLeapYear(2021)); 


    
    
/*
run:
    
true
false
    
*/

 

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Answer 2

function printLeapYear(year) {
     if (year % 4 == 0) {
        if (year % 100 == 0) {
            if (year % 400 == 0)
                console.log("Leap year");
            else
                console.log("Not a leap year");
        }
        else
            console.log("Leap year");
    }
    else
        console.log("Not a leap year");
}
 
printLeapYear(2020);
 
printLeapYear(2021); 
 
 
     
     
/*
run:
     
"Leap year"
"Not a leap year"
     
*/

 

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Answer 3

function isLeapYear(year) {
    return new Date(year, 1, 29).getDate() === 29;
}
 
console.log(isLeapYear(2020)); 
 
console.log(isLeapYear(2021)); 
 
 
     
     
/*
run:
     
true
false
     
*/

 

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