Let's Discuss About JavaScript "Weird Parts"

Question

Strange ways JavaScript behaves that makes it quite hard to grasp but ultimately makes it a very beautiful and amazing programming language. e.g

console.log(1 < 2 < 3) and console.log(3 < 2 < 1)

both prints: true

Very confusing and weird.....Lol

Answer 1

It's because of JavaScript Associativity and Coercion.

Associativity:
How JavaScript reads code upon encountering multiple operators of the same precedence, whether to read: Left-to-Right or Right-to-Left.
For the example above the associativity is Left-to-Right.

e.g

(1 < 2 < 3)

1 and 2 are first compared and the result of the two later compared to 3. So
( 1 < 2 < 3 ) => ( true < 3 )

The result above triggers JavaScript inbuilt weird part, Coercion.

Coercion:
How implicitly JavaScript automatically convert data types. One of the reasons why JavaScript is a dynamically typed language. Just the same "var" word could be used to declare and assigned values of any type ( string, boolean, number, symbol, undefined).

So the result above: ( true < 3 )

JavaScript infers a comparison between a
boolean: true and number: 3 and automatically coerce the boolean: true => 1, before compared to the number. Hence:

( true < 3 ) => ( 1 < 3 )

So the whole process is this:

( 1 < 2 < 3 ) => ( true < 3 ) => ( 1 < 3 ) => true

Also:

( 3 < 2 < 1 ) => ( false < 1 ) => ( 0 < 1 ) => true

That's it! go on share any weird JavaScript behavior.

Answer 2

why is it like that

Answer 3

can you provide me some best angular Js reference

Answer 4

I didn't understand ..

Answer 5

SGS gvahvshsdhz jwbshshjsbsbzjssbhshhhshfyusb gwgs

Answer 6

new hello