“Programs must be written for people to read, and only incidentally for machines to execute.”
— Harold Abelson, Structure and Interpretation of Computer Programs
Logical operators are generally symbols or words which connect two or more expressions that allow a program to make a decision based on a given set of conditions.
Logical operators usually control the program flow and are frequently used with the if, while, or some other control statement.
Three (3) Types Logical Operators
- Logical AND operator (&&): For logical AND operators, both conditions must be true for the statement to be true. If one of them is false, then the program will return false.
//Example
let a, b;
a = 3; b = 4;
console.log(a === 3 && b === 4) //TRUE
console.log(a === 3 && b === 3) //FALSE
2. Logical OR operator ( || ): For logical OR operators, one of the operands just have to be true for the statement to be true.
//Using variables from our first example
console.log(a === 3) || (b === 4) //TRUE
console.log(a === 3) || (b === 3) //TRUE
3. Logical NOT operator ( ! ): This is used to reverse the logical state of its operands. If a condition is true, then the Logical Not will make it false.
//Using variables from our previous example
console.log(!(a === 3)) //FALSE
LANGUAGE | AND | OR | NOT |
C++ | && | || | ! |
C# | && | || | ! |
Java | && | || | ! |
JavaScript | && | || | ! |
PHP | && | || | ! |
Python | and | or | not |
Swift | && | || | ! |