Ruby && operator on integers

Question

does anyone know the meaning of && and || when applied to integers in Ruby?

Here are some examples in IRB when && and || are applied to integers:

>> 1 && 2
=> 2

>> 2 && 1
=> 1

>> 15 && 20
=> 20

>> 20 && 15
=> 15

>> 0 && -1
=> -1

>> -1 && -2
=> -2

>> 1 || 2
=> 1

>> 2 || 1
=> 2

Answer 1

The boolean operators &&, ||, and and or are among the few that are not syntactic sugar for method calls, and thus, there are no different implementations in different classes.

In other words: they behave exactly the same for all objects, i.e. they behave the same for Integers as they do for Strings, Hashes, Floats, Symbols, and any other object.

a && b

evaluates to a if a is falsey (and will not evaluate b at all in this case), otherwise it evaluates to b (and only then will b be evaluated)

a || b

evaluates to a if a is truthy (and will not evaluate b at all in this case), otherwise it evaluates to b (and only then will b be evaluated)

nil and false are falsey, everything else is truthy, including 0, 0.0, '', [], and {}.