Logical operators in Ruby (and, or, not), (&&, ||, !) - Code Maven
In Ruby there are two sets of logical operators: and, or, not &&, ||, ! Normally you can use either set of the operators but it is not recommended to mix them in the same expression. The difference between the two sets is the precedence. The operators that are words (and, or, not) are lower in the operator precedence table than the other three.