const carSales = [
 { make: 'Maruti', model: 'Dzire', sales: 20610 },
 { make: 'Maruti', model: 'Baleno', sales: 14532 },
 { make: 'Hyundai', model: 'i10 Grand', sales: 14417 },
 { make: 'Maruti', model: 'Swift', sales: 12057 },
 { make: 'Hyundai', model: 'Elite i20', sales: 11012 },
 { make: 'Hyundai', model: 'Creta', sales: 9248 }
];

//array with just the names of all the car model.
let carModels = [];
for (let i = 0; i < carSales.length; i++) {
    carModels.push(carSales[i].model);
}
console.log(carModels);

//array of car made by Maruti.
let marutiCarModels = [];
for (let i = 0; i < carSales.length; i++) {
    if(carSales[i].make == 'Maruti')
       marutiCarModels.push(carSales[i]);
}
console.log(JSON.stringify(marutiCarModels));

//Total car sales
let totalCarSales = 0;
for (let i = 0; i < carSales.length; i++) {
    totalCarSales = totalCarSales + carSales[i].sales;
}
console.log(totalCarSales);