What's going on with JavaScript's OR operator?

Question

|| Shouldn’t the operator return true or false? Why does JavaScript return an object? What’s going on? Could you please help me explain

Answer 1

Javascript logical operatorscan be used in non-Boolean environments.

Although the && and || operators can be used in non-Boolean environments, if their return values ​​can be converted to Boolean values, they can also be considered Boolean operations

(from logical operator)

For non-Boolean environments:

When there is one false, return the value on the false side
When there are two false, return the value before the operator (left side);
When there are two true, return the value after the operator (right side) value.

(derived from the return value of logical operations in JavaScript (logical AND &&, logical OR ||, logical NOT!))

Answer 2

First of all, you need to know the false values ​​in js: 0, false, '', null, undefined, NaN
In combination or operation
When one.nextElementSibing is not any of the above values, next = one.nextElementSibing; otherwise it is equal to one. nextSibing