| Developed by the
English mathematician and computer pioneer George Boole, a Boolean
consists of operators such as "AND", "OR",
"NOT" and "XOR". Generally, Booleans are commonly 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. In
addition to using a Boolean operator many search engines also
substitute "AND" with "+" and "NOT"
with "-", so using our same above example a user could
type "computer help +dos" to achieve the same results.
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" therefore the result would be
FALSE. |
FALSE |
| OR |
Free |
Help |
The above example data has both
"free" and "help", however the OR
Boolean only requires one or the other therefore this
would be TRUE. |
TRUE |
| OR |
Expensive |
Help |
Although "expensive" is
not in the example data, it still does contain
"help" therefore this would still remain
TRUE. |
TRUE |
| NOT |
Free |
|
The above example does contain
"free", therefore the result would be FALSE. |
FALSE |
| NOT |
Expensive |
|
The above example does not contain
"expensive", therefore this result would be
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, therefore
this is FALSE. |
FALSE |
| XOR |
Expensive |
Help |
The above example does not contain
"expensive", however does contain
"help", therefore this would be TRUE. |
TRUE |
|
Also see: Conditional
statement, Operator, Programming
definitions, XOR
|
|
| Resolved | Were you able to locate the answer to your questions? |
|
|