Day 3: Scope & Default Parameters

Daily Objective

Understand variable accessibility across scopes and assign fallback default parameters.

1. Scope (Global, Function, Block)

const globalVar = 'Accessible everywhere';

function demoScope() {
  const functionVar = 'Only inside demoScope';
  if (true) {
    const blockVar = 'Only inside this if block';
    console.log(blockVar);
  }
  // console.log(blockVar); // ReferenceError!
}

2. Default Parameters

function greetUser(name = 'Guest', greeting = 'Welcome') {
  return `${greeting}, ${name}!`;
}
console.log(greetUser()); // "Welcome, Guest!"
console.log(greetUser('Alice')); // "Welcome, Alice!"

Daily Hands-on Practice (70%)

1. Create a function with 2 default parameters and invoke it with 0, 1, and 2 arguments.
2. Intentionally try reading a block-scoped variable outside its curly braces.