values() method is used to return an array whose elements are the enumerable property values found on the object. The ordering of the properties is the same as that given by the object manually is a loop is applied to the properties. Object.
Refs are a function provided by React to access the DOM element and the React element that you might have created on your own. They are used in cases where we want to change the value of a child component, without making use of props and all.
Why ! Is false?
! evaluates to false because the reference is truthy.  can be converted to an number (0 in this case) which is falsey. Therefore: the condition passes as equal.
How do you declare variables?
To declare (create) a variable, you will specify the type, leave at least one space, then the name for the variable and end the line with a semicolon ( ; ). Java uses the keyword int for integer, double for a floating point number (a double precision number), and boolean for a Boolean value (true or false).
Is JS call by reference?
Should I use VAR or let?
The main difference between the two though is that let deals with block scope whereas var deals with global scope or function scope depending on where it’s declared. As long as your variable isn’t declared within any function, var can be used again anywhere else in your code.
Is Let better than VAR?
let allows you to declare variables that are limited in scope to the block, statement, or expression on which it is used. This is unlike the var keyword, which defines a variable globally, or locally to an entire function regardless of block scope.
Is Let hoisted?
Let and const hoisting
Variables declared with let and const are also hoisted, but unlike for var the variables are not initialized with a default value of undefined . Until the line in which they are initialized is executed, any code that accesses these variables will throw an exception.