Comparators

Lets now focus on the conditional part:

if (country === "France") {
    ...
}

The conditional part is the variable country followed by the three equal signs (===). Three equal signs tests if the variable country has both the correct value (France) and also the correct type (String). You can test conditions with double equal signs, too, however a conditional such as if (x == 5) would then return true for both var x = 5; and var x = "5";. Depending on what your program is doing, this could make quite a difference. It is highly recommended as a best practice that you always compare equality with three equal signs (=== and !==) instead of two (== and !=).

Other conditional tests:

• x > a: is x bigger than a?

• x < a: is x less than a?

• x <= a: is x less than or equal to a?

• x >=a: is x greater than or equal to a?

• x != a: is x not a?

• x: does x exist?

Logical Comparison

In order to avoid the if-else hassle, simple logical comparisons can be utilised.

let topper = marks > 85 ? "YES" : "NO";

In the above example, ? is a logical operator. The code says that if the value of marks is greater than 85 i.e. marks > 85 , then topper = YES ; otherwise topper = NO . Basically, if the comparison condition proves true, the first argument is accessed and if the comparison condition is false, the second argument is accessed.