Boolean
Developed by the English mathematician and computer pioneer
George Boole, a
Boolean consists of operators such as
AND,
OR,
NOT, and
XOR. Booleans are
often used in programming and today in Internet
search engines. Boolean expressions are expressions that result in the value of either TRUE or FALSE.
As mentioned above a user can use Boolean searches to help locate more exact matches in Internet searches. For example, a user could search for
computers help and DOS, which would search for any document containing computer help that also contain the word
DOS.
Performing Boolean searches often help users find results relating more to what
the user may need to find.
Below is an example chart that help explains the Boolean operations even more by giving examples and explanations of each of the different Boolean situations.
| Example data = "Computer Hope is a location where users can find free computer help and information" |
| Boolean |
Value_1 |
Value_2 |
Explanation |
Results |
| AND |
Free |
Help |
Because the above example data contains both "free" and "help" the results would be TRUE. |
TRUE |
| AND |
Expensive |
Help |
Although the above example does have "help", it does not contain "expensive,"
which makes the result FALSE. |
FALSE |
| OR |
Free |
Help |
The above example data has both "free" and "help" but the OR Boolean only requires one or the other,
which makes this TRUE. |
TRUE |
| OR |
Expensive |
Help |
Although "expensive" is not in the example data, it still does contain "help,"
which makes the TRUE. |
TRUE |
| NOT |
Free |
|
The above example does contain "free",
which makes the result FALSE. |
FALSE |
| NOT |
Expensive |
|
The above example does not contain "expensive,"
which makes the result TRUE. |
TRUE |
| XOR |
Free |
Help |
The above example contains both "free" and "help", the XOR Boolean only requires one or the other, but not both,
making this FALSE. |
FALSE |
| XOR |
Expensive |
Help |
The above example does not contain "expensive" but does contain "help,"
which makes this TRUE. |
TRUE |
|
Also see: Ampersand, Bitwise operators, Conditional statement, Data type, False, Operator, Programming definitions, True, XOR
