For Loop Transforming

Transforming is the process of changing the item of an array to another format.

You can go through all items in JavaScript using either:

for...of loop is easier to read, but you do not have access to index variable.

Exercise 1

Given an array of number (data parameter), and a number (num parameter), multiple each item in the array by the num parameter, then returns them.

Examples:

data: [2,3,2,6], num: 2 -> [4,6,4,12]
data: [5,3,1], num: 6 -> [30,18,6]
data: [7,7,7], num: 7 -> [49,49,49]

export default function multiplyAll(data, num) {
  // TODO
}

Exercise 2

Returns an array of string that describe each person in dataset in the format of '{name}, aged {age}'. If age is not available, returns '{name}' only.

An example of the dataset is

js
const dataset = [
  {
    name: 'Malcolm',
    age: 32,
  },
  {
    name: 'Esther',
    age: 10,
  },
  {
    name: 'Richie',
    age: 50,
  },
  {
    name: 'Audrey',
  },
];

When the example is provided to the function, it should returns:

js
['Malcolm, aged 32', 'Esther, aged 10', 'Richie, aged 50', 'Audrey']

export default function getPersonsSummary(dataset) {
  // TODO
}

Exercise 3

Returns an array that contains the original items in the dataset, with each item is added with a isUnderage property, where person with age < 18 would have isUnderage: true, otherwise would be `false.

An example of the dataset is

js
const dataset = [
  {
    name: 'Malcolm',
    age: 32,
  },
  {
    name: 'Esther',
    age: 10,
  },
  {
    name: 'Richie',
    age: 50,
  },
  {
    name: 'Audrey',
  }
];

When the example is provided to the function, it should returns:

js
[
  {
    name: 'Malcolm',
    age: 32,
    isUnderage: false
  },
  {
    name: 'Esther',
    age: 10,
    isUnderage: true
  },
  {
    name: 'Richie',
    age: 50,
    isUnderage: false
  },
  {
    name: 'Audrey',
    isUnderage: false
  },
]

export default function addAgeTagging(dataset) {
  // TODO
}

Exercise 4

Given an array of strings representing integers, returns a new array where each element is an object with two properties, the original integer string and the integer value squared.

Example:

Given numberStrings is ['1', '2', '3', '4', '5'], the function should returns:

js
[
  {
    original: '1',
    squared: 1,
  },
  {
    original: '2',
    squared: 4,
  },
  {
    original: '3',
    squared: 9,
  },
  {
    original: '4',
    squared: 16,
  },
  {
    original: '5',
    squared: 25,
  },
]

export default function processIntegers(numberStrings) {
  // TODO
}

Exercise 5

Given an array of object representing products, where each object has id, name, and price property, returns a new array of objects with a discounted price by applying a 10% discount.

Example:

Given products is:

js
[{id: 5, name: 'orange', price: 10}, {id: 20, name: 'banana', price: 100}]

the function should returns:

js
[
  {
    id: 5,
    name: 'orange',
    price: 9
  },
  {
    id: 20,
    name: 'banana',
    price: 90
  }
]

export default function applyDiscount(products) {
  // TODO
}