freeCodeCamp Challenge Guide: Understand Functional Programming Terminology

Understand Functional Programming Terminology


Problem Explanation

Just as in the last challenge, you must call the getTea method and store it in a variable. Only this time, you have 2 variables to store 2 seperate sets of data in. You will see that the getTea() function is the same as before, only now it takes in 2 seperate parameters. The first parameter is a function, so we will need to pass in either the prepareGreenTea() function or the prepareBlackTea() function, followed by the second parameter numOfCups which can be input as an integer.


Hints

Hint 1

In this exercise we are assigning the result of a higher order function to variables. To do this we call a function with a callback function as a parameter.

Hint:

const basketOne = makeBasket(addFruit, 10) 

Solutions

Solution 1 (Click to Show/Hide)
/**
 * A long process to prepare green tea.
 * @return {string} A cup of green tea.
 **/
const prepareGreenTea = () => "greenTea";

/**
 * Get given number of cups of tea.
 * @param {function():string} prepareTea The type of tea preparing function.
 * @param {number} numOfCups Number of required cups of tea.
 * @return {Array<string>} Given amount of tea cups.
 **/
const getTea = (prepareTea, numOfCups) => {
  const teaCups = [];

  for (let cups = 1; cups <= numOfCups; cups += 1) {
    const teaCup = prepareTea();
    teaCups.push(teaCup);
  }

  return teaCups;
};

// Add your code below this line
const tea4GreenTeamFCC = getTea(prepareGreenTea, 27); // :)
const tea4BlackTeamFCC = getTea(prepareBlackTea, 13); // :)
// Add your code above this line

console.log(tea4GreenTeamFCC, tea4BlackTeamFCC);

Code Explanation

In the solution above we passed in the functions prepareGreenTea() and prepareBlackTea() as parameters or callback functions for the getTea() functions being assigned to our two constant variables tea4BlackTeamFCC
and tea4GreenTeamFCC.
This way no global variables are changed, and we have the option to add an unlimited number of different choices of prepareTea() methods since it is a callback function being passed to the higher order function of getTea().

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