Basic Algorithm P2

The fun and challenging part of FCC continues, Basic Algorithm Part 2.

Find the Longest Word in a String

• Return the length of the longest word in the provided sentence
• Your response should be a number
• Given hints: use .split() and .length

Challenge

function findLongestWord(str) {
  return str.length;
}

findLongestWord("The quick brown fox jumped over the lazy dog");

The problem with a string is that it is immutable. .split(" ") is going to turn a string str into an array arr. Adding space in between the quotes is important, because I would like for the string to be split into per a word, and not into per a character or into letters. Use for loop to go through each word, and to get number of characters in each word would need a .length.

function findLongestWord(str) {
  var arr = str.split(" ");
  for (var i = 0; i < arr.length; i++) {
  }
  return str.length;
}

findLongestWord("The quick brown fox jumped over the lazy dog");

Now i short for my “index” will loop through each word in an array arr, and what I want to do is put down a code that will count the number of indexes in element. My goal is to keep the biggest word, while bypass smaller words. I am going to create a variabe biggest and set it to 0. Whenever word’s bigger than the biggest, set that word to biggest.

function findLongestWord(str) {
  var arr = str.split(" ");
  var biggest = 0;
  for (var i = 0; i < arr.length; i++) {
    if (arr[i].length > biggest) {
      biggest = arr[i].length;
    }
  }
  return biggest;
}

findLongestWord("The quick brown fox jumped over the lazy dog");
// 6

Title Case a Sentence

• Return the provided string with the first letter of each word capitalized. Make sure the rest of the word is in lower case
• For the purpose of this exercise, you should also capitalize connecting words like “the” and “of”
• Given hint: use .split()

function titleCase(str) {
  return str;
}

titleCase("I'm a little tea pot");

I am supposed to aim for // I'm A Little Tea Pot. Programming, I would think, is like being a chef, gotta to do a food prep before I cook up ingredients altogether to make it taste great. I am going to toLowerCase() and .split() the string at the same time to lowercase everything and arraize it a new varaible strLoAr. A for loop to go through each word with an i is needed. One more for loop for a letter in word using j, an index within an index/element. Let’s set up a prep right now.

function titleCase(str) {
  var strLoAr = str.toLowerCase().split(" ");
  for (var i = 0; i < strLoAr.length; i++) {
    for (var j = 0; j < strLoAr[i].length; j++) {
    }
  }
  return str;
}

titleCase("I'm a little tea pot");

Okay, now let’s replace first letter of each word with a capitalized letter. In order to capture the first letter and manipulate it, is using a conditional statement if (j === 0) in second for loop. I am going to remove the first letter by using .slice() and rename the remaining strLoAr to a new variable fixed. Extract the first letter from each word in a former array strLoAr, and captialize it and then put into a new variable capped. I realized that I would need a new empty array, so I created and named it titled to apply .push(). I want to add capped to fixed in titled. Always check each new variable with a console.log() to ensure it comes as desired.

function titleCase(str) {
  var strLoAr= str.toLowerCase().split(" ");
  var capped;
  var fixed;
  var titled = [];
  for (var i = 0; i < strLoAr.length; i++) {
    for (var j = 0; j < strLoAr[i].length; j++) {
      if (j === 0) {
        fixed = strLoAr[i].slice(1);
        capped = strLoAr[i][j].toUpperCase();
      }
    } titled.push(capped + fixed);
  } return titled.join(" ");
}

titleCase("I'm a little tea pot");

// 'I\'m A Little Tea Pot'

In some consoles like repl.it, it will show backslash in “I’\m” but it won’t render.

Return Largest Numbers in Arrays

• Return an array consisting of the largest number from each provided sub-array
• For simplicity, the provided array will contain exactly 4 sub-arrays
• Remember you can iterate through an array with a simple for loop, and access each member with array syntax arr[i]
• Should return an array
• Given Hint: Comparison Operators

function largestOfFour(arr) {
  return arr;
}

largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);

Outline below every challenge is usually directly copied and pasted from freecodecamp, and it suggested me to use arr[i]. Of course I am going to use a for loop to iterate through arrays. I came up with two different solutions. First one was easy and I felt like I cheated. If it works, then it isn’t a cheat, but would be better to learn how to do the long way. I am going to put down the first solution and explain quickly. I used Math.max to solve the problem.

function largestOfFour(arr) {
  var tallest= [];
  var max;
  for (var i = 0; i < arr.length; i++) {
    max = Math.max.apply(null, arr[i]);
    tallest.push(max);
  } return tallest;
}

largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
// [ 5, 27, 39, 1001 ]

I set a new array named tallest. I processed to create a for loop. I looked through stackoverflow on how to use Math.max and it suggested me to use .apply(). I decided that I would use a new variable max to make it easier. So I set max to Math.max.apply(null, arr[i]) inside for loop and then push it into array tallest. Return tallest outside of for loop to allow loop to complete. null is an intentional absence of any object value, allowing computer to ignore completely, or bypass. .apply(thisArg, [argsArray]) is the default and I am using Math.max as a function so I used null. That was the quick way.

Let’s do the long way. Setting a new empty array tallest since there are four different arrays and I want to pluck largest number out of each, and put them into one array. First for loop to iterate through an array with arrays inside. Recall the challenge on the top of this page, “Find the Longest Word”, it is almost the same idea. I created a new variable max to hold the biggest number in. I set max to 0. Second for loop to iterate through indexes/[element]s in each array. if an element arr[i][j] is bigger than max, set it to max. Outside the second for loop, push it into tallest array. outside both loops, return tallest.

function largestOfFour(arr) {
  var tallest = [];
  for (var i = 0; i < arr.length; i++) {
    var max = 0;
    for (var j = 0; j < arr[i].length; j++) {
    if (arr[i][j] > max){
      max = arr[i][j];
    }
  } tallest.push(max);
  } return tallest;
}

largestOfFour([[4, 5, 1, 3], [13, 27, 18, 26], [32, 35, 37, 39], [1000, 1001, 857, 1]]);
// [ 5, 27, 39, 1001 ]