const inventory = {
  items: ['apple', 'banana', 'orange'],
  [Symbol.iterator]: function() {
    let index = 0;
    const items = this.items;
    
    return {
      next: function() {
        return index < items.length ?
          { value: items[index++].toUpperCase(), done: false } :
          { done: true };
      }
    };
  }
};

const result = [...inventory].join(' + ');
console.log(result);

const obj = {};
const sym1 = Symbol('description');
const sym2 = Symbol('description');

obj[sym1] = 'Value 1';
obj[sym2] = 'Value 2';
obj.regularProp = 'Regular';

const allKeys = Object.getOwnPropertySymbols(obj).length + Object.keys(obj).length;
const comparison = sym1 === sym2;

console.log(allKeys + ',' + comparison);

const team = {
  members: ['Alice', 'Bob', 'Charlie'],
  leader: 'Diana',
  [Symbol.iterator]: function*() {
    yield this.leader;
    for(const member of this.members) {
      yield member;
    }
  }
};

let names = [];
for (const person of team) {
  names.push(person);
}

console.log(names.join(', '));

function processData(data) {
  try {
    if (!data) {
      throw new TypeError('Data is required');
    }
    
    if (data.status === 'error') {
      throw new Error('Invalid status');
    }
    
    return data.value.toUpperCase();
  } catch (err) {
    if (err instanceof TypeError) {
      return 'Type Error';
    }
    return err.message;
  }
}

console.log(processData({ status: 'error', value: 'test' }));

const obj = {
  name: 'Original',
  greet() {
    return function() {
      console.log(`Hello, ${this.name}`);
    };
  },
  arrowGreet() {
    return () => {
      console.log(`Hello, ${this.name}`);
    };
  }
};

const globalThis = { name: 'Global' };
const newObj = { name: 'New' };

const regularFn = obj.greet();
const arrowFn = obj.arrowGreet();

regularFn.call(newObj);

const calculator = {
  value: 10,
  add: function(x) {
    return this.value + x;
  },
  multiply: function(x) {
    return this.value * x;
  }
};

const add5 = calculator.add;
const double = calculator.multiply.bind(calculator);
const triple = calculator.multiply.bind({value: 3});

console.log(add5(2) + double(3) + triple(4));

const a = 9007199254740991n; // MAX_SAFE_INTEGER as BigInt
const b = 2n;
const c = a + b;

const result = [
  a === 9007199254740991,
  a + 1n === 9007199254740992n,
  typeof c,
  c > Number.MAX_SAFE_INTEGER,
  BigInt(9007199254740992) - BigInt(9007199254740991)
];

console.log(result);

const team = {
  name: 'Eagles',
  players: ['Smith', 'Johnson', 'Williams'],
  coach: { name: 'Brown', experience: 12 },
  stats: { wins: 10, losses: 6 }
};

const { 
  name: teamName, 
  players: [firstPlayer, , thirdPlayer],
  coach: { name },
  stats: { wins, draws = 0 }
} = team;

console.log(`${teamName}-${firstPlayer}-${thirdPlayer}-${name}-${wins}-${draws}`);