Define a function isFive that will return true if a number is equal to 5 and false if it is not.
Write a function whisper that takes in a string and returns a “whispered” version of that string.
HINT: try using the .toLowerCase() function on a string to see what it does!
Write a function isOdd that takes in a number as an argument and returns true if the number is odd and returns false otherwise.
Write two versions of this function, using conditionals and without using conditionals.
function isOdd(num) {
return Math.abs(num) % 2 === 1 ? true : false;
}
function isOdd2(num) {
if (Math.abs(num) % 2 === 1) {
return true;
} else {
return false;
}
}Define a function logBetween(lowNum, highNum) that will print every number from lowNum to highNum, inclusive. Inclusive means that the range includes lowNum and highNum.
Hint: this function only needs to print using console.log it does not need to return.
Write a function averageOfFour(num1, num2, num3, num4) that takes in four numbers. The function should return the average of all of the numbers.
function averageOfFour (num1, num2, num3, num4) {
let arr = [num1, num2, num3, num4];
return arr.reduce((a,b) => (a+b)) / arr.length;
}Write a function printFives(max) that prints out the multiples of 5 that are less than max. Try to solve this in two ways, using a conditional (if) and without using a conditional.
function printFives(max) {
for (var i = 0; i < max; i++) {
if (i % 5 === 0) {
console.log(i);
}
}
}
function printFives2(max) {
for (var i = 0; i < max; i+= 5) {
console.log(i);
}
}Write a function logBetweenStepper(min, max, step) that takes in 3 numbers as parameters. The function should print out numbers between min and max at step intervals. See the following examples.
Hint: this function only needs to print using console.log it does not need to return.
function logBetweenStepper(min, max, step) {
for (var i = min; i <= max; i+=step) {
console.log(i);
}
}Write a function threeOrSeven that takes in a number and returns true if the number is divisible by either 3 or 7 and false otherwise.
Write two versions of this function, using conditionals and without using conditionals.
Write a function sumArray(array) that takes in an array of numbers and returns the total sum of all the numbers.
Write a function combineArray(array1, array2) that takes in two arrays of numbers and returns the two arrays combined into a single array.
Hint: Use the Array#concat method but be aware that calling this method won’t permanently change, also known as mutate, either array.
Write a function doubler(numbers) that takes an array of numbers and returns a new array where every element of the original array is multiplied by 2.
function doubler(numbers) {
let result = [];
for (var i = 0; i < numbers.length; i++) {
result.push(numbers[i] * 2);
}
return result;
}Write a function, countVowels(word), that takes in a string word and returns the number of vowels in the word. Vowels are the letters “a”, “e”, “i”, “o”, “u”.
function countVowels(word) {
const VOWEL = "aeiou";
let count = 0;
for (var i = 0; i < word.length; i++) {
if (VOWEL.indexOf(word[i]) > -1) {
count++;
}
}
return count;
};So far you’ve learned how to write your own loops but there are some methods that will iterate for you. One such method is the String#indexOf() method.
Write a function isSubstring that takes in two strings, searchString and subString. The function should return true if subString is a part of thesearchString, regardless of upper or lower case, and false if otherwise.
function isSubstring(searchString, subString) {
let lower = searchString.toLowerCase();
return (lower.indexOf(subString) > -1 ) ? true : false;
}Define a function fizzBuzz(max) that takes a number and prints every number from 0 to max that is divisible by either 3 or 5, but not both.
function fizzBuzz(max) {
for (var i = 0; i < max; i ++) {
if (i % 3 === 0 && i % 5 === 0) {
continue;
} else if (i % 3 === 0 || i % 5 === 0) {
console.log(i);
}
}
}So far you’ve learned how to write your own loops but there are some methods that will iterate for you. One such method is the Array#indexOf() method. The indexOf() method returns the first index that it finds for the element given, or -1 if the element is not found.
Write a function named wordWithinArray(array,word) using Array#indexOf. The function takes in both a word and an array of words as arguments and returns a boolean that returns true if that string is located inside of the array, or false if it does not.
Write a function echo that takes in a string and console.logs that string “echo-ized”.
function echo(string) {
console.log string.toUpperCase() + " ... " + string + " ... " + string.toLowerCase();
}Write a function named eitherStringIncluded(sentence, word1, word2) that accepts a sentence and two words as arguments. The eitherStringIncluded function should return true if either word1 or word2 is found in the sentence, and false if neither is found. Hint: the String#includes method will return true or false if a given string is included in another string.
function eitherStringIncluded(sentence, word1, word2) {
return (sentence.includes(word1) || sentence.includes(word2)) ? true : false;
}Pig Latin is a fun take on the English language where you move any consonant cluster from the start of the word to the end of the word; when words begin on a vowel, you simply add “-yay”. Vowels are “aeiou”.
Write a function pigLatinWord that takes in a word string and translates the word into Pig Latin. For this problem use the String#slice method. The slice() method extracts a section of a string and returns it as a new string, without modifying the original string.
Hint: Remember the String#includes method!
function pigLatinWord(word) {
const VOWEL = "aeiou";
if (VOWEL.indexOf(word[0]) > -1) {
return word + "yay";
} else {
for (var i = 0; i < word.length; i++) {
if (VOWEL.indexOf(word[i]) > -1) {
return word.slice(i) + word.slice(0,i) + "ay";
}
}
}
}The following function is named aCounter(word). The function takes in a word and returns the number of a’s within that word. The function counts both lowercase (a) and uppercase (A). Your job is to translate the following function to use a for loop instead of the while loop it is currently using. If you forget the syntax for a for loop go back and check out the reading.
function aCounter(word) {
let index = 0;
let count = 0;
while (index < word.length) {
let char = word[index];
if (char === "a" || char === "A") {
count += 1;
}
index++;
}
return count;
}
function aCounter(word) {
word = word.toLowerCase();
let count = 0;
for (var i = 0; i < word.length; i++) {
if (word[i] === "a") {
count ++;
}
}
return count;
}Define a function isPrime(number) that returns true if number is prime. Otherwise, false. A number is prime if it is only divisible by 1 and itself.
function isPrime(number) {
let array = [];
for (var i = 0; i <= number; i++) {
if (number % i === 0) {
array.push(i);
}
}
return (array.length === 2) ? true : false;
}The following function is named eCounter(word). The function takes in a string word and returns the number of e’s in the word. The function counts both lowercase (e) and uppercase (E). Your job is to translate the following function to use a while loop instead of a for loop! If you forget the syntax for a while loop go back and check out the reading.
function eCounter(word) {
word = word.toLowerCase();
let i = 0
let counter = 0;
while (i <= word.length - 1) {
if (word[i] === "e") {
counter ++;
}
i++;
}
return counter;
}