Using conditionals in Array definitions

The tertiary conditional: "?"

function getMonthLength(month,year){
d= new Date(month+" 1, "+year);
ml=[31,isLeapYear(year)? 29:28,31,30,31,30,31,31,30,31,30,31];
return ml[d.getMonth()];
}
function isLeapYear(year){
return new Date(year, 1, 29).getMonth() == 1;
}


How many days this month?

var months = ['January','February','March','April','May','June','July','August', 'September','October','November','December'];

var this_month_length =
getMonthLength(months[new Date().getMonth],new Date().getFullYear())

Try it