Module 1: Array Methods 1, 2,3,4,5

Question 1

Write a function called “getNthElement”.

Given an array and an integer, “getNthElement” returns the element at the given integer, within the given array.

Answer 1

function getNthElement(array, n) {
return array[n];
}

Question 2

Write a function called “getFirstElement”.

Given an array, “getFirstElement” returns the first element of the given array.

Notes:

Answer 2

function getFirstElement(array) {
return array[0];
}

Question 3

Write a function called “getLastElement”.

Given an array, “getLastElement” returns the last element of the given array.

Answer 3

function getLastElement(array) {
return array[array.length-1];
}

Question 4

Write a function called “addToFront”.

Given an array and an element, “addToFront” adds the given element to the front of the given array, and returns the given array.

Answer 4

function addToFront(arr, element) {
arr.unshift(element);
return arr;
}

Question 5

Write a function called “addToBack”.

Given an array and an element, “addToBack” returns the given array with the given element added to the end.

Answer 5

function addToBack(arr, element) {
arr.push(element);
return arr;
}

Question 6

Write a function called “computeAreaOfARectangle”.

Given the length and width of a rectangle, “computeAreaOfARectangle” returns its area.

Answer 6

function computeAreaOfARectangle(length, width) {
return length * width;
}

Question 7

Write a function called “computePerimeterOfARectangle”.

Given a length and a width describing a rectangle, “computePerimeterOfARectangle” returns its perimter.

Answer 7

function computePerimeterOfARectangle(length, width) {
return (length \* 2) + (width \* 2);
}

Question 8

Write a function called “computePerimeterOfATriangle”.

Given 3 sides describing a triangle, “computePerimeterOfATriangle” returns its perimter.

Answer 8

function computePerimeterOfATriangle(side1, side2, side3) {
return side1 + side2 + side3;
}

Question 9

Write a function called “computeTripledAreaOfARectangle”.

Given a length and width of a rectangle, “computeTripledAreaOfARectangle” returns the rectangle’s area, multiplied by 3.

Answer 9

function computeTripledAreaOfARectangle(length, width) {
return (length * width) * 3;
}

Question 10

Write a function called “computePerimeterOfACircle”.

Given the radius of a circle, “computePerimeterOfACircle” returns its perimeter.

Notes:

Math.PI can be used for pi.

Answer 10

function computePerimeterOfACircle(radius) {
return 2 \* Math.PI \* radius;
}

Question 11

Write a function called “computeAreaOfACircle”.

Given the radius of a circle, “computeAreaOfACircle” returns its area.

Answer 11

function computeAreaOfACircle(radius) {
return Math.PI * radius * radius;
}

Question 12

Write a function called “computePower”.

Given a number and an exponent, “computePower” returns the given number, raised to the given exponent.

Answer 12

function computePower(num, exponent) {
return num ** exponent;
}

Question 13

Write a function called “computeSquareRoot”. Given a number, “computeSquareRoot” returns its square root.

Answer 13

function computeSquareRoot(num) {
return Math.sqrt(num);
}

Question 14

Write a function called “doubleSquareRootOf”. Given a number, “doubleSquareRootOf” returns double its square root.

Answer 14

function doubleSquareRootOf(num) {
return (Math.sqrt(num)) * 2;
}

Question 15

Write a function called “getLengthOfThreeWords”.

Given 3 words, “getLengthOfThreeWords” returns the sum of their lengths.

Answer 15

function getLengthOfThreeWords(word1, word2, word3) {
return word1.length + word2.length + word3.length;
}

Question 16

Write a function called “joinArrays”.

Given two arrays, “joinArrays” returns an array with the elements of “arr1” in order, followed by the elements in “arr2”.

Answer 16

function joinArrays(arr1, arr2) {
return arr1.concat(arr2);
}

Question 17

Write a function called “getElementsAfter”.

Given an array and an index, “getElementsAfter” returns a new array with all the elements after (but not including) the given index.

Answer 17

function getElementsAfter(array, n) {
return array.slice(n + 1);
}

Question 18

Write a function called “getElementsUpTo”.

Given an array and a index, “getElementsUpTo”, returns an array with all the elements up until, but not including, the element at the given index.

Answer 18

function getElementsUpTo(array, n) {
return array.slice(0,n);
}

Question 19

Write a function called “getAllElementsButFirst”.

Given an array, “getAllElementsButFirst” returns an array with all the elements but the first.

Answer 19

function getAllElementsButFirst(array) {
return array.slice(1, array.length);
}

Question 20

Write a function called “getAllElementsButLast”.

Given an array, “getAllElementsButLast” returns an array with all the elements but the last.

Answer 20

function getAllElementsButLast(array) {
return array.slice(0, array.length - 1);
}

Question 21

Write a function called “removeFromFront”.

Given an array, “removeFromFront” returns the given array with its first element removed.

Answer 21

function removeFromFront(arr) {
arr.shift();
return arr;
}

Question 22

Write a function called “removeFromBackOfNew”.

Given an array, “removeFromBackOfNew” returns a new array containing all but the last element of the given array.

Answer 22

function removeFromBackOfNew(arr) {
return arr.slice(0, arr.length-1);
}

Question 23

Write a function called “removeFromFrontOfNew”.

Given an array, “removeFromFrontOfNew” returns a new array containing all but the first element of the given array.

Answer 23

function removeFromFrontOfNew(arr) {
return arr.slice(1, arr.length);
}

Question 24

Write a function called “countCharacter”.

Given a string input and a character, “countCharacter” returns the number of occurences of a given character in the given string.

Answer 24

**function countCharacter(str, char) {
var count = 0;
 for (var i = 0; i \< str.length; i++) {
 if (str[i] === char) {
 count++;
 }
}
 return count;
}**