? JavaScript Booleans

What is a Boolean?

• A Boolean represents a logical entity and can have two values:

  • true

  • false

Creating Boolean Values

let isActive = true;let isLoggedIn = false;

Boolean in Expressions

• Results from comparisons or logical operations.

console.log(5 > 3);  // trueconsole.log(10 === "10"); // false

Boolean Conversion (Truthy and Falsy)

Values convert to Boolean automatically in conditions:

Example:

if ("") {  console.log("This won't run");  // Because "" is falsy}if ("hello") {  console.log("This will run");  // Because non-empty string is truthy}

Boolean Object vs Boolean Primitive

• Avoid using new Boolean(). It creates an object, which is always truthy, even if false is stored inside.

const b1 = new Boolean(false);console.log(b1);          // [Boolean: false]if (b1) {  console.log("Runs");    // This runs, because objects are truthy!}

Use boolean primitives (true or false) instead.

Logical Operators with Booleans

• && (AND)

• || (OR)

• ! (NOT)

console.log(true && false); // falseconsole.log(true || false); // trueconsole.log(!true);         // false

Want examples on truthy/falsy in conditions or logical operator tricks?