It’s Halloween time! I told my husband that I would dress up as a boolean. I would be a ghost (boo) and have in one hand the word true and the other hand the word false. He is a programmer and this went directly over his head.
Anyways, I’m going to be Salt Bae now.
WHAT IS A BOOLEAN?
Booleans, however are not scary. It’s a data type for a conditional statement value that is either true or false. Boolean expressions allow us to conditionally excute a branch of code. By default the value is set to false. It is named after George Boole, an English mathematician who helped establish modern symbolic logic - now called Boolean algebra.
COMPARISON/RELATIONAL OPERATORS
| Operator | Function |
|---|---|
== |
Equals to |
!= |
Not equal to |
< |
Less than |
> |
Greater than |
<= |
Less than or equal to |
>= |
Greater than or equal to |
BOOLEAN/LOGICAL OPERATORS
Boolean operators are used to define the relationship between your search terms. They can be used to narrow or broaden your search. There are three main operators are AND ( && ), OR ( ||) and NOT ( !).
The order of operation is read from left to right. Both && and || use short circuit evaluation. For &&, as soon as an expression evaulates as false, arguments following are not evaluated and the entire expression evaluates as false. For ||, as soon as an expression evaluates as true, arguments following are not evaluated and the entire expression evaulates as true.
AND ( && )
Values on both sides of the symbol must be true. Otherwise the expression is false.
Examples:
9 == 9 && 8 == 8 TRUE
true && false FALSE
Short Circuit Example:
1 == 2 && reboot_computer
OR ( ||)
One of the values on either side of the symbol must be true. Otherwise the expression is false.
Examples:
true || false TRUE
8 == 9 || 1 == 0 FALSE
Short Circuit Example:
country = user_input || 'USA'
NOT ( ! )
Reverses the logic. If the condition is true, it will now be false.
Examples:
!!true = TRUE
!true = FALSE