Comparison Operators

You should already be familiar with these inequality operators, and they work as you would expect in JavaScript:

5 < 6; // evaluates to true
5 > 6; // evaluates to false
5 >= 6; // evaluates to false
5 <= 6; // evaluates to true

The equality operators, however, are a bit... strange. To compare two values to see if they are exactly the same, use the strict equality (===) and strict inequality (!==) operators:

5 === 6; // evaluates to false
5 !== 6; // evaluates to true

The "normal" equality (==) and inequality (!=) operators are a bit more... flexible:

5 == 6; // evaluates to false
5 == "5"; // evaluates to true

5 != 6; // evaluates to true
5 != "5"; // evaluates to false

The "strict equals" (===) and "strict not equals" (!==) compare both the value and the type. The "loose equals" (==) and "loose not equals" (!=) attempt to convert and compare values of different types. With the loose versions, the string '5' and the number 5 are considered "equal", which, in good code, is usually not what you want.

This is a fairly unique quirk of the JavaScript language.

You can read more about how == works if you're interested, but I'd recommend sticking with === and !== in nearly all cases.