Kevin Powell - Community•2y ago

Codewar challenge

I have to keep the first word within the output capitalized only if the original word was capitalized, but my code is trasnforming every first word capitalized. What am doing wrong? expected output in the image

function toCamelCase(str){
  let splittingWord = str.split(/-|_/);
  
  let camelCaseString = "";
  
  for(let i = 0; i < splittingWord.length; i++){
    const upperLetters = splittingWord[i].toUpperCase()[0];
    const lowerLetters =  splittingWord[i].slice(1).toLowerCase();
        
     if (i === 0) {
      camelCaseString += upperLetters + lowerLetters;
    } else {
      camelCaseString += splittingWord[i].toUpperCase()[0]+lowerLetters;
    }
   
}
  console.log(camelCaseString);

}
toCamelCase("the-stealth-warrior");

function toCamelCase(str){
  let splittingWord = str.split(/-|_/);
  
  let camelCaseString = "";
  
  for(let i = 0; i < splittingWord.length; i++){
    const upperLetters = splittingWord[i].toUpperCase()[0];
    const lowerLetters =  splittingWord[i].slice(1).toLowerCase();
        
     if (i === 0) {
      camelCaseString += upperLetters + lowerLetters;
    } else {
      camelCaseString += splittingWord[i].toUpperCase()[0]+lowerLetters;
    }
   
}
  console.log(camelCaseString);

}
toCamelCase("the-stealth-warrior");

38 Replies

Joao•2y ago

Well, one way to approach this is: check if the first letter is lower case, in which case you don't need to do anything, or uppercase, in which case you also don't need to do anything. In other words, skip the first iteration and you should be done.

SsteOP•2y ago

Can you explain in more detail? I didn't understand

Joao•2y ago

What I mean is that the first letter should be left untouched, right? So in the first iteration of the loop you don't actually need to do anything there. You'd still need to change the returned value a bit to use that first fragment, plus the modified ones. I don't think you can combine spoiler tags with code on Discord.

SsteOP•2y ago

It still confuses for me what you are trying to say

Joao•2y ago

Ok, so you are splitting str into several fragments or splittingWords whatever you want to call it. What I'm saying is that you already know that the first segment does not need to be changed. Therefore the loop where you turn the first letter on each fragment to uppercase, doesn't need to start at 0. Because you know that the first fragment should not be modified at all. The exercise says that if it's lowercase leave it as is, but you should also leave it as is if it's already uppercase.

SsteOP•2y ago

It makes sense

Joao•2y ago

In your screenshot, the-stealth-warrior the firs segment is the and that word doesn't get modified. The same is true for the others.

SsteOP•2y ago

It's better if I just delete the upperLetters variable

Joao•2y ago

So, 1) split the words 2) iterate over the resulting array starting on the second index 3) return the first segment combined with the modifications you made during the loop Well I don't know if you need that variable or not to be honest, but that's the steps I would take to make this work.

SsteOP•2y ago

Thanks, I will try it

vince•2y ago

If you get stuck: https://codepen.io/vince1444/pen/gOQwmgJ?editors=1111

Joao•2y ago

A bit heavy on the use of array methods for my taste, I think there must be a way to simplify that.

vince•2y ago

Definitely could be haha. I work a decent bit with React so I feel like most of the stuff you use in there are array methods

Joao•2y ago

Yeah definitely. I had to give it a try so here's my version: https://codepen.io/D10f/pen/qBQamaG

vince•2y ago

Ohhh definitely much cleaner! I like it 🙂

Joao•2y ago

I like to come back to the basics for simple things 🙂

Gashy•2y ago

This is my take on one, you can take it out of the template string if you want it a bit more readable https://codepen.io/gashydev/pen/mdQrmrV

Joao•2y ago

@sstephanyyy If you have it, share it!

SsteOP•2y ago

function toCamelCase(str) {
  let camelCaseString = "";

  if (str) {
    let splittingWord = str.split(/[-_]/);
    
    for (let i = 0; i < splittingWord.length; i++) {
      const word = splittingWord[i];
      const capitalizedWord = (i === 0) ? word : word.charAt(0).toUpperCase() + word.slice(1).toLowerCase();
      camelCaseString += capitalizedWord;
    }
  } else {
    return camelCaseString;
  }
}

function toCamelCase(str) {
  let camelCaseString = "";

  if (str) {
    let splittingWord = str.split(/[-_]/);
    
    for (let i = 0; i < splittingWord.length; i++) {
      const word = splittingWord[i];
      const capitalizedWord = (i === 0) ? word : word.charAt(0).toUpperCase() + word.slice(1).toLowerCase();
      camelCaseString += capitalizedWord;
    }
  } else {
    return camelCaseString;
  }
}

I still didn't complete the exercise

SsteOP•2y ago

it says this

Joao•2y ago

I think it's time for a break then. After so long, it's best to walk away for a while and let you brain work it out in the background.

SsteOP•2y ago

I did this. I have come back has a few minutes

Joao•2y ago

In the meantime I have a couple of suggestions to improve code quality overall. First, since you are checking for the existence of str you can make that return earlier:

function toCamelCase(str) {
  if (!str) return '';

  // rest of the code 
}

function toCamelCase(str) {
  if (!str) return '';

  // rest of the code 
}

This will avoid additional nesting. I highly suggest this video on the topic: https://www.youtube.com/watch?v=CFRhGnuXG-4

SsteOP•2y ago

humm, makes sense okay, I will watch it

Joao•2y ago

I think you have the right idea of what's going on, you're almost there. I'll give you a hint of how I did it: start the loop at 1 instead.

SsteOP•2y ago

I noticed it haha let me try

Joao•2y ago

If you start the loop at one you are essentially skipping the first fragment of the original string. So you can safely update the rest as you need without worrying whether it's the first iteration or not.

SsteOP•2y ago

like this? I am feeling so stupid because I can't solve an easy problem haha

function toCamelCase(str) {
  let camelCaseString = "";

  if (!str) {
    const words = str.split(/[-_]/);
    let res = "";

  for (let i = 1; i < words.length; i++) {
    const firstLetter = words[i][0].toUpperCase();
    const rest = words[i].slice(1).toLowerCase();
    res += firstLetter + rest;
  }

    }
}

function toCamelCase(str) {
  let camelCaseString = "";

  if (!str) {
    const words = str.split(/[-_]/);
    let res = "";

  for (let i = 1; i < words.length; i++) {
    const firstLetter = words[i][0].toUpperCase();
    const rest = words[i].slice(1).toLowerCase();
    res += firstLetter + rest;
  }

    }
}

Joao•2y ago

That looks right. Don't feel that way, we all have our own frame of reference. "Easy" it's very relative. Don't worry about checking for the existence of str yet. You can add that later. Just focus on the main task for now

SsteOP•2y ago

yessssssssssss, I did it!

function toCamelCase(str) {
  let camelCaseString = "";

  if (str) {
    const words = str.split(/[-_]/);
    let res = "";

    for (let i = 1; i < words.length; i++) {
      const firstLetter = words[i][0].toUpperCase();
      const rest = words[i].slice(1).toLowerCase();
      res += firstLetter + rest;
    }

    camelCaseString = words[0] + res;
  }

  return camelCaseString;
}

function toCamelCase(str) {
  let camelCaseString = "";

  if (str) {
    const words = str.split(/[-_]/);
    let res = "";

    for (let i = 1; i < words.length; i++) {
      const firstLetter = words[i][0].toUpperCase();
      const rest = words[i].slice(1).toLowerCase();
      res += firstLetter + rest;
    }

    camelCaseString = words[0] + res;
  }

  return camelCaseString;
}

SsteOP•2y ago

SsteOP•2y ago

thanks for all the help João

Joao•2y ago

No worries, congrats! You can check now the other answers and compare it. There's always many different ways to do things to you can see how other people approach the same problem. Well I guess in codewars you can do that as well, but I found that over there a lot of people tend to go for the absolute most concise answer... which is not always realistic or practical.

SsteOP•2y ago

yes. I will have to remake this problem all by myself to try to understand everything better hey, one more question...do u think solve this problems are useful or is it better to build real projects?

Joao•2y ago

I guess it depends on the person. I did for a while but I found more useful to build real projects. A lot of these exercises come up naturally anyway. But on the other hand from time to time it also useful to flex your mind with things you are not used to work with. Something that I find useful when coming to Discord and try to help out is that I need to solve issues that I didn't run into on my own, so that helps.

Gashy•2y ago

Yeah I was about to say even though I've worked with web dev for a few years commercially I might delve into some of these code war things a bit deeper myself. There is a lot of stuff in JS that you dont actually use (or rarely when you do), so niche things like this can sometimes help in the long run, even if its introducing you to something new. It's also a good way to find/test out multiple solutions for the end product, exactly like how Vince, Joao and myself showed above, we all came to a similar end point but our solutions vary in different methods.

vince•2y ago

Clean! I like this one

Joao•2y ago

I like to try different languages to expand myself a bit. I made this version in C just for fun as I've been practicing it for a while:

char* toCamelCase(const char* str)
{
    static char res[100];

    int i = 1;
    int j = 1;

    while (str[i] != '\0')
    {
        if (str[i] == '_' || str[i] == '-' || str[i] == ' ')
            res[j] = toupper(str[++i]);
        else
            res[j] = tolower(str[i]);

        i++;
        j++;

    };

    res[0] = str[0];
    res[j] = '\0';

    return res;
}

char* toCamelCase(const char* str)
{
    static char res[100];

    int i = 1;
    int j = 1;

    while (str[i] != '\0')
    {
        if (str[i] == '_' || str[i] == '-' || str[i] == ' ')
            res[j] = toupper(str[++i]);
        else
            res[j] = tolower(str[i]);

        i++;
        j++;

    };

    res[0] = str[0];
    res[j] = '\0';

    return res;
}

Gaming

Programming

Codewar challenge