- Assignment 1.2.1 - Array Higher Order Methods
- From Scratch
- Question 1: logEachValue
- Question 2: getUserById
- Question 3: getEvenNumbers
- Question 4: getSquaredTotal
- Question 5: makePeopleHappy
- Question 6: hasOnlyEvenNumbers
- Question 7: doubleEveryNumber
- Question 8: getIndexOfApple
- Question 9: convertToBooleans
- Question 10: numberOfCharacters
- Question 11: anyGreaterThan10
- Question 12: roundAll
- Question 13: removeJerkFromCompany
- Question 14: onlyStrings
- Question 15: chosenCoordinates
- Question 16: stringsToLength
- Question 17: totalGreaterThanGiven
- Question 18: numberOfLongWords
- Modify
- Short answers
This assignment is all about training you to recognize the types of situations that will call for specific array methods. DO NOT USE ANY LOOPS HERE. Loops can obviously be used in the real world, but we want you to recognize when an array method would be more readable/handy.
Every question should be answered with one of the array methods you learned today. Some might even require more methods that you learned last week (like splice or push). But this assignment is all about building familiarity with the array methods. Fluency is the goal here.
REMEMBER: NOT A SINGLE LOOP SHOULD BE USED IN THIS ASSIGNMENT. ONLY ARRAY METHODS.
All of these can be answered in about one or two lines. That's how powerful these methods are!
These prompts should be pretty straightforward, but they are getting a little vague. That's because we want you to start relying not on these prompts, but the actual tests themselves in from-scratch.spec.js. We know they look scarier than prompts, but that how you code at a company. The better you get at reading tests, the more you'll stand out from the Jr. Dev crowd.
Given an array of values, you must console log the value and the index in a single string like: Value: [VALUE], index: [INDEX].
Do not modify the original array.
Given and array of user objects and a number, return the object with the given id property. If an object isn't found, return undefined.
Do not modify the original array.
Given an array of numbers, return a new array of only the even numbers from the array.
Do not modify the original array.
Given an array of numbers, return the sum of all the numbers squared. Meaning, square each number before adding it to the total.
Do not modify the original array.
Given an array of people objects, mutate it so that each object has their isHappy property set to true. return nothing.
Given an array of numbers, return true if every number is even, otherwise return false.
Do not modify the original array.
Given an array of numbers, return a new array where every element is doubled.
Do not modify the original array.
Given an array of food objects, return the number index of the food item with a name of "apple". If it is not found, return -1.
Do not modify the original array.
Given an array of values, return a new array where each value is converted to a boolean. That means that if the value is truthy, the new value should be true and if the value is falsy, the new value should be false.
Do not modify the original array.
Given a string return an object with the count of each character in the string. All characters must be tracked, even spaces. Meaning, don't skip over spaces. Be sure to check the tests on this one to make sure you're getting the right object output.
Given an array of numbers, return true if any of the numbers are greater than 10. Otherwise, return false.
Do not modify the original array.
Given an array of numbers, return a new array where every number is rounded to the nearest integer.
Do not modify the original array.
Given an array of people objects, mutate it so that the person with the personality property of "jerk" is removed from the array. Return nothing.
Given an array of values, return a new array where only strings are kept.
Do not modify the original array.
Given an array of coordinate arrays and a number, select the first coordinate pair that adds up to the specified number. Return undefined if no pair adds up to the number.
Do not modify the original array.
Given an array of strings, return a new array where each string is replaced by its length.
Do not modify the original array.
Given an array of numbers and a number, return true if the sum of the array is greater than the given number. Otherwise, return false.
Do not modify the original array.
Given an array of words, return the number of words that are longer than 4 characters. If no words are longer than 4 characters, return 0.
Do not modify the original array.
Looks like someone didn't get the memo about the new array methods in modify.js. They've written some code that uses loops. Refactor the code to use the array methods you learned today. Make sure to use the right one though!
Your only guide for this section is the existing code and the tests in modify.spec.js. This is very much how real world refactors work, take the opportunity to practice!
The questions are about what situations are best for which methods. The better you get at this now, the faster you can code in a stressful interview!