How to write ELSE IF using ? : in javascript

var value = Cond1 ? True1 : (Cond2 ? True2 : (Cond3 ? True3 : Other));

The () notations make the expression above clear, but not a must do.

Demo:

var a;
for (var i = 0; i < 5; ++i) {
  a = (i === 0 ? 'Zero' : (i === 1) ? 'one' : (i === 2) ? 'two' : 'Other');
  console.log(a);
}

However, I'd suggest use

var str;
if () {
  str = ...
} else if() {
  str = ...
}
// Or .append/.html  ...etc.
$TBL.text('....' + str + '.....');

For readability.

With switch your code will be easier to read and it's also easy to add or change a case.

var i = 0;
switch(i) {
    case 0:
        //i is 0
        break;
    case 1:
        //i is 1
        break;
    case 2:
        //i is 2
        break;
    case 3:
        //i is 3
        break;
    case 'foobar':
        //this is not an integer
        break;
    default:
        //i is not one of the above
}

You can use iternary operator in the following way to get the result:

Check_1 ? true_1 : (Check_2 ? true_2 : (Cond_3 ? true_3 : ....));

you can use ElseIf condition in javascript like this

var time = new Date().getHours();
    if (time < 10) {
        greeting = "Good morning";
    } else if (time < 20) {
        greeting = "Good day";
    } else {
        greeting = "Good evening";
    }