Learn Data Types and Conditionals Lesson J

More complex conditional statements might include multiple conditions. That is why logical operators are used to combine multiple conditions. The logical operators are &&, || and ! which are used to represent and, or and not respectively.

The logical operator || is used to combine two boolean conditions. It returns true if at least one of the conditions is true. Otherwise, it returns false:

let a = 5;
let b = 10;
let c = 15;

if (a > b || a > c) {
  console.log("At least one of the conditions is true");
} else {
  console.log("Both of the conditions are false");
}

The logical operator && is used to combine two boolean conditions. It returns true only if both of the conditions are true. Otherwise, it returns false:

let a = 5;
let b = 10;
let c = 15;

if (a < b && a < c) {
  console.log("Both of the conditions are true");
} else {
  console.log("At least one of the conditions is false");
}

The logical operator ! is used to negate a boolean condition. It returns true if the condition is false. Otherwise, it returns false:

let a = 5;
let b = 10;

if (!(a > b)) {
  console.log("The condition is false");
} else {
  console.log("The condition is true");
}

In the above example, the extra pair of parentheses is used to make the code more readable. It is not necessary to use them.