madbernard: a long angled pier (Default)
Challenge 5 was, given a number between 1 and 1000, add up all the numbers inclusive in that set. Obviously I could repurpose Matt Larsh's recursive function to do this, so I did so, and it worked first try. Woo! Though, no one else seems to be doing +=. I wonder if this would be super wrong if I wasn't recursing and thus seeing it only once each function call? Or do they just like num + SimpleAdding(stuff)?
function SimpleAdding(num) {
  if (num === 1) {
    return 1;  
  }
  else {
    return num += SimpleAdding(num - 1);
  }      
}
Challenge 6 was one I hadn't yet solved in Free Code Camp: Capitalize every word in a string. I abandoned a couple different paths while trying for speed, and eventually came up with this answer that seems cludgy:
function LetterCapitalize(str) { 
  var foo = str.split('');
  var bar = [];
  bar.push(foo[0].toUpperCase());
  for(var i = 1; i < foo.length; i++) {
    if (foo[i - 1] === ' ') {
      bar.push(foo[i].toUpperCase());
    }
    else {
      bar.push(foo[i]);
    }    
  }
  console.log(bar.join(''));
  return bar.join('');
}
LetterCapitalize('to see how to enter arguments in JavaScript');
I tried replacing the space in the if statement with /\s/ and that didn't work, nor did /\s/g; I'm not sure why not.

One of my abandoned paths was to do a str.replace(regex, function) but I wasn't getting the function to work... So I was super curious to see what Matt Larsh did, and sure enough he did something cool:
function LetterCapitalize(str) { 
  return str.replace(/\b[a-z]/g,function(c){return c.toUpperCase()});
}
That "\b" was something I thought should exist, but didn't find: the signal for "match a word boundary". I just tried /\b\w/g and that works, too; I suppose his way is better, though, since it limits the capitalization to only things that we absolutely know need capitalizing. Unless if \w includes accented letters and other slightly less usual things? My RegEx skillz are not yet l33t and m4d.
madbernard: a long angled pier (Default)
The next Free Code Camp exercise is to find the length of the longest word in a string (and all of their test strings are free of anything but letters and single spaces). Good points: I had no trouble getting the shape of the solution, and split totally worked great. Actually doing the proper syntax for Reduce required a lot of searching, though, and eventually I basically copied a bit from this webpage about getting comfy with arrays. I should work through that website sometime... Most of the failed reduce trials I don't have copies of, but one that I don't understand is that when I had a 0 in the place I thought was for initial value, right after the anonymous function and before the console.log error-catching readout, here: }, 0);
console.log(foo.length);
what I got out of the function was only 0. Baffling. Below is code that works. :)

function findLongestWord(str) {
var words = str.split(' ');
var foo = words.reduce(function(prevWord, thisWord){
if (thisWord.length > prevWord.length) {
return thisWord;
}
else {
return prevWord;
}
});
console.log(foo.length);
return foo.length;
}

findLongestWord('The quick brown fox jumped over the lazy dog');
madbernard: a long angled pier (Default)
So, 4 was trivial, which was great: make a function that factorializes numbers. Like, 5! is 1 * 2 * 3 * 4 * 5 = 120.

function factorialize(num) {
for (var i = (num - 1); i > 0; i--) {
num *= i;
}
return num;
}

factorialize(5);

But 5... I feel like I shouldn't have to make my own function that takes an array and jams it all into a single string without commas separating the bits. But the concat stuff I was looking at in the Mozilla Developer Network wasn't working that way (even though their example shows it should. So baffled).

And I feel like there must be some way to not declare like 7 variables... But I couldn't figure out how to chain these methods/functions. Anyway: here it is, a function that checks if a statement is a palindrome (ignoring all the non-letter things! The RegEx stuff was honestly fun learning).

function reverseString(str) {
var reverseStr = '';
for (var i = str.length - 1; i > -1; i--){
reverseStr += str[i];
}
return reverseStr;
}

function arrToRevStr(arr) {
var str = '';
for (var i = arr.length - 1; i > -1; i--){
str += arr[i];
}
return str;
}

function palindrome(str) {
var cleanStrArray = /(\w)/g.exec(str);
var cleanStr = arrToRevStr(cleanStrArray);
var cleanStrLow = cleanStr.toLowerCase();

var reverseStr = reverseString(str);
var cleanReverseStrArray = /(\w)/g.exec(reverseStr);
var cleanReverseStr = arrToRevStr(cleanReverseStrArray);
var cleanReverseStrLow = cleanReverseStr.toLowerCase();

if (cleanStrLow == cleanReverseStrLow) {return true;}
else {return false;}
}

palindrome("eye");

May 2016

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