var myArray = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20];

for(key in myArray) {
    if(item % 3 == 0) {
        console.log("Fizz");
    }
    else if(item % 5 == 0 {
        console.log("Buzz");
    }
    else if ( (item % 3 == 0) && (item % 5 == 0) ) {
        console.log("FizzBuzz");
    }
    else {
        console.log(i);
    }