Question

JavaScript - Sorting Assignment (arrays, classes, functions and higher order functions)

Note: Please make sure to use the ES6 keyword style => instead of the older function. For variables please use keyword let, not var, class and within the constructor, not function.

Instructions:

- Create a new JavaScript file and name it “Objects.js”

- Create a class and make sure to use “names” as the identifier.

- Create a constructor with the following elements:

first ( value passed will be String )
last ( value passed will be String )
age ( value passed will be Numeric )

Note: Constructor will assign values for the three elements and use the keyword “this”.

- Create a function and use “printObject” as the identifier.

The function will have the following three input parameters:

allNames, sortType, message

Note: It will sort the array of objects (allNames) using sortType as the key to how the array objects will be sorted.

The sort options are first , last , age, none.

Will print the message to the console

- Use a loop to print out the array by index ascending and display the values located in the elements: first, last, age for each accessed index (refer to the example on the bottom of the page).

- Create a function main with no input parameters.

main:

Create the empty array using the identifier "allNames"

Using the push() method, load 4 new objects of names to the array allNames, populating the fields first , last , age (for example: allNames.push( new names("Cammo", "Hammer", 39));

- Call printObject, passing the array , sort method as a string ( options are first, last, age, none )

- Last line of the script, would be the call to the main

Example output (all console messages should match):

C:\Users\ Desktop\JavaScript>node Objects.js Objects by Index: Cammo Hammer 39 Zoe Cicco 21 Piper Balmer 49 Jasper Thorn 10 Objects by First Name: Cammo Hammer 39 Jasper Thorn 10 Piper Balmer 49 Zoe Cicco 21 Objects by Last Name: Piper Balmer 49 Zoe Cicco 21 Cammo Hammer 39 Jasper Thorn 10 Objects by Age: Jasper Thorn 10 Zoe Cicco 21 Cammo Hammer 39 Piper Balmer 49

Answer 1

//declare the class

class names {

  //declare the constructor

  constructor(_first, _last, _age) {

    //initialise the attributes of the class

    this.first = _first;

    this.last = _last;

    this.age = _age;

  }

}

let printObject = (allNames, sortType, message) => {

  console.log("\n" + message);

  //if sortType is first

  if (sortType == "first") {

    allNames.sort((a, b) => {

      if (a.first < b.first)

        // ascending

        return -1;

      if (a.first > b.first) return 1;

      return 0;

    });

    //print the objects

    for (name of allNames) {

      console.log(`${name.first} ${name.last} ${name.age}`);

    }

  }

  //if sortType is last

  if (sortType == "last") {

    allNames.sort((a, b) => {

      if (a.last < b.last)

        // ascending

        return -1;

      if (a.last > b.last) return 1;

      return 0;

    });

    //print the objects

    for (name of allNames) {

      console.log(`${name.first} ${name.last} ${name.age}`);

    }

  }

  // sort by age

  if (sortType == "age") {

    allNames.sort((a, b) => {

      return a - b;

    });

    //print the objects

    for (name of allNames) {

      console.log(`${name.first} ${name.last} ${name.age}`);

    }

  }

  // sort type is none

  if (sortType == "none") {

    for (name of allNames) {

      console.log(`${name.first} ${name.last} ${name.age}`);

    }

  }

};

let main = () => {

  //create the array

  let allNames = [];

  //insert the objects

  allNames.push(new names("Cammo", "Hammer", 39));

  allNames.push(new names("Zoe", "Cicco", 21));

  allNames.push(new names("Piper", "Balmer", 49));

  allNames.push(new names("Jasper", "Thorn", 10));

  //call the print function

  printObject(allNames, "none", "Objects by Index:");

  printObject(allNames, "first", "Objects by First Name:");

  printObject(allNames, "last", "Objects by Last Name:");

  printObject(allNames, "age", "Objects by Age:");

};

main();

Objects by Index: Cammo Hammer 39 Zoe Cicco 21 Piper Balmer 49 Jasper Thorn 10 Objects by First Name: Cammo Hammer 39 Jasper Thorn 10 Piper Balmer 49 Zoe Cicco 21 Objects by Last Name: Piper Balmer 49 Zoe Cicco 21 Cammo Hammer 39 Jasper Thorn 10 Objects by Age: Piper Balmer 49 Zoe Cicco 21 Cammo Hammer 39 Jasper Thorn 10