Question

Describe how equality comparisons in JavaScript works using == and === and describe the difference between these operators..

Comparison operators are used by Javascript to evaluate conditions with the result being a Boolean: true or false. Other operators do exist but this article will focus on equality comparisons.

Is equal to

== compares two values together to see if they are the same. Values being numbers, strings, or Booleans. Getting the wrong comparison is likely to happen with == because it can’t distinguish between data type, so it’s best to use the strict equal to operator. Conversion takes place thats why ‘3’ == 3 can be true, the 3 converts to a string.

'Goodbye' == 'bye' // will return false not same string
'Goodbye' == 'Goodbye' // will return true same string
'Goodbye' == 'goodbye' // will return false not same string caps different
'3' == 3 // returns true reason to avoid this operator 

Strict equal to

=== on the other hand compares not only the value but the data type also which prevents the mishaps that == has. Conversion doesn’t take place, a 3 stays a number and so on. Use this operator 99% of the time in your code.

"3" === 3 // returns false  because although same value not the same data type
"3" === "3" // returns true same data type and value 

Example

When you open the codepen it will ask for a number if you guess the right number it tells you. This is one way that you can you the strict equal operator to get a comparison.

See the Pen === in action by oscar (@nopity) on CodePen.