Logical Operators
Logic operators are used to find the logic between variables in JavaScript.There are three logical operators in JavaScript: || (OR), && (AND), ! (NOT).
The AND operator
The AND operator (&&) returns true if both expressions are true, otherwise it returns false.
Example
<html> <body> <p id="and"></p> <script> var a = 200; var b = 300; document.getElementById("and").innerHTML = (a > 100 && b <500) + "<br>" + (a < 100 && b <50); </script> </body> </html>
Output
true false
The OR operator
The OR operator gives value true if one or both expressions are true.
Example
<html> <body> <p id="or"></p> <script> var x = 200; var y = 300; document.getElementById("or").innerHTML = (x == 200 || y == 300) + "<br>" + (x == 200 || y == 0) + "<br>" + (x == 0 || y == 0) </script> </body> </html>
Output
true true false
The NOT operator
The NOT operator gives false for true values and true for false values.
Example
<html> <body> <p id="not"></p> <script> var x = 200; var y = 300; document.getElementById("not").innerHTML = !(x < y) + "<br>" + !(x > y); </script> </body> </html>
Output
false true