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 (&& or AND) connects two boolean expressions and returns true only if both expressions are true.
  • For example, if A=true and B=true, then A AND B will be true. If either A or B is false, A AND B will be false.

Logical OR Operator

  • The logical OR operator (|| or OR) connects two boolean expressions and returns true if at least one of the expressions is true.
  • For instance, if A=true and B=false, then A OR B will be true. It will also be true if both A and B are true. It will only be false if both A and B are false.

Logical NOT Operator

  • The logical NOT operator (! or NOT) is used before a single boolean expression and inverts the value of the expresssion.
  • For example, if A=true, then NOT A will be false. If A=false, then NOT 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, and False OR True all result in true, with only False OR False yielding false.
  • For the NOT operation, the truth table would demonstrate the inversion of the original boolean value: NOT False yields true, and NOT True yields false.

Applications in Decision Making

  • Logical operators are critical in decision making constructs in programming, such as if, while, and for 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.