将.map方法应用于对象数组

array.map(callback(currentValue[, index[, array]])[, thisArg])

const persons = [
  { name: 'Alice', age: 25 },
  { name: 'Bob', age: 30 },
  { name: 'Charlie', age: 35 }
];

const names = persons.map(person => person.name);
console.log(names); // ['Alice', 'Bob', 'Charlie']

const grades = [
  { score: 80 },
  { score: 90 },
  { score: 70 }
];

const levels = grades.map(grade => {
  if (grade.score >= 90) {
    return 'A';
  } else if (grade.score >= 80) {
    return 'B';
  } else {
    return 'C';
  }
});

console.log(levels); // ['B', 'A', 'C']

const products = [
  { name: 'Apple', price: 10 },
  { name: 'Banana', price: 5 },
  { name: 'Orange', price: 8 }
];

const updatedProducts = products.map(product => {
  return {
    name: product.name,
    price: product.price * 1.1
  };
});

console.log(updatedProducts);
// [
//   { name: 'Apple', price: 11 },
//   { name: 'Banana', price: 5.5 },
//   { name: 'Orange', price: 8.8 }
// ]