JavaScript === vs == : Does it matter which "equal' operator I use?

I'm using JSLint to go through some horrific JavaScript at work and it's returning a huge number of suggestions to replace == with === when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement.

Why does this go into an infinite loop?

I'm a teacher, and yesterday a student wrote the following code:

Java += operator

Until today I thought that for example:

i += j;

is just a shortcut for:

Make the plus sign a string in java

So I want the plus sign to be stored as a string and displayed to the screen later; so in this case I have

What does | in this code mean?

function foo() {}

var bar = foo <| function() {};

This is the first time I've seen something like this. What does <| mean?

Source: https://github.com/allenwb/ESnext-experiments/blob/master/ST80collections-exp1.js

Source: Tips4all

"AND" vs "&&" as operator

Actually, I am facing a codebase where developpers decided to use ' AND ' and ' OR ' instead of ' && ' and ' || '. I know that there is difference in operators precedence ( && goes before ' and '), but with given framework (prestashop to be precise) is clearly not a reason. So, my question: which version are you using? Is ' and ' more readable than ' && '? || there is ~ difference?

Java - Order of Operations - Using Two Assignment Operators in a Single Line

What are the order of operations when using two assignment operators in a single line?