Javascript Tutorial Development Tutorials, Guides & Insights

• The user must be logged in (isLoggedIn is true).
• The user's account must not be suspended (isSuspended is false).

let number = 12;
if (number > 10 && number % 2 === 0) {
  console.log("The number is greater than 10 and even.");
}

let isLoggedIn = true;
let isSuspended = false;

if (isLoggedIn && !isSuspended) {
  console.log("User can log in.");
} else {
  console.log("Access denied.");
}
            
        

• Create variables a and b with values 12 and 4.
• Perform all arithmetic operations and log the results.

     let a = 12;
     let b = 4;
     console.log("Addition:", a + b);        // 16
     console.log("Subtraction:", a - b);     // 8
     console.log("Multiplication:", a * b);  // 48
     console.log("Division:", a / b);        // 3
     console.log("Modulus:", a % b);         // 0
            
        

• Arrow Functions (ES6):

  const multiply = (a, b) => a * b;
  console.log(multiply(4, 7)); // 28
            
        

Use the typeof operator to check the type of a value.

  console.log(typeof "Hello"); // string
  console.log(typeof 42); // number
  console.log(typeof null); // object (this is a historical quirk)
  console.log(typeof undefined); // undefined
            
        

     function test() {
       var y = 20;
       console.log(y); // 20
     }
     console.log(y); // Error: y is not defined
            
        

let name = "Alice";
console.log(name);

const BIRTH_YEAR = 1990;
// BIRTH_YEAR = 2000; // Error: Assignment to constant variable