Logical Operators
Understanding Logical Operators
- Logical operators form a key aspect of boolean logic, which is fundamental to computer programming.
- A logical operator is a symbol or word used to connect two or more boolean expressions (true or false expressions).
- There are three primary logical operators: AND, OR, and NOT.
Logical AND Operator
- The logical AND operator (
&&
orAND
) connects two boolean expressions and returns true only if both expressions are true. - For example, if
A=true
andB=true
, thenA AND B
will be true. If eitherA
orB
is false,A AND B
will be false.
Logical OR Operator
- The logical OR operator (
||
orOR
) connects two boolean expressions and returns true if at least one of the expressions is true. - For instance, if
A=true
andB=false
, thenA OR B
will be true. It will also be true if bothA
andB
are true. It will only be false if bothA
andB
are false.
Logical NOT Operator
- The logical NOT operator (
!
orNOT
) is used before a single boolean expression and inverts the value of the expresssion. - For example, if
A=true
, thenNOT A
will be false. IfA=false
, thenNOT A
will be true.
Truth Tables
- Truth tables are useful tools for visualising and understanding the outcomes of logical operators.
- For the AND operation, a truth table would show that only
True AND True
results in true, with all other combinations yielding false. - For the OR operation, a truth table would present that
True OR True
,True OR False
, andFalse OR True
all result in true, with onlyFalse OR False
yielding false. - For the NOT operation, the truth table would demonstrate the inversion of the original boolean value:
NOT False
yields true, andNOT True
yields false.
Applications in Decision Making
- Logical operators are critical in decision making constructs in programming, such as
if
,while
, andfor
statements. - They help formulate logical conditions, allowing the program to decide on a specific course of action based on these conditions.
Bear in mind that mastery of logical operators will not only benefit you in Computer Science but also in general problem-solving and logical reasoning tasks.