Convert every first letter of every word into uppercase

Question

I have the following question:

Write a titleize(text) function that converts every first letter of every word into uppercase.

ex: titleize("this IS just A Text"); // correct output -> (This Is Just A Text.)

I was able to capitalize the first letters of each word only that I have no idea how to get change the rest of the letters to lower case.

I found a little verbose my solution if you have something more elegant please feel free.

Follow the code so you can see what I’m doing:

function titleize(text) {

    // Convertendo primeira letra em maiuscula.
    text = text.charAt(0).toUpperCase() + text.slice(1);

    for (var i = 0; i < text.length; i++) {
        if (text.charAt(i) ===" ") {

            // Convertendo letra após o ESPAÇO em maiuscula
            var charToUper = text.charAt(i+1).toUpperCase();

            // Colocando texto de antes do ESPAÇO na variável
            var sliceBegin = text.slice(0, (i+1));

            // colocando o texto de depois do ESPAÇO na variável
            var sliceEnd = text.slice(i + 2);

            // Juntando tudo
            text = sliceBegin + charToUper + sliceEnd;

        } else {

            // NAO CONSIGO PENSAR EM COMO TRANSFORMAR O RESTANTE DAS LETRAS EM MINUSCULA
        }   
    }
    return text;
}
console.log (titleize("this IS just A tExT"));

Note that I have done nothing in relation to the central letters of each word, so they return both upper and lower case :/

My current output on the console:

How could I solve this problem ?

Answer 1

How about something like:

function titleize(text) {
    var loweredText = text.toLowerCase();
    var words = loweredText.split(" ");
    for (var a = 0; a < words.length; a++) {
        var w = words[a];

        var firstLetter = w[0];
        w = firstLetter.toUpperCase() + w.slice(1);

        words[a] = w;
    }
    return words.join(" ");
}

Being very minimalist, it can be written as well:

function titleize(text) {
    var words = text.toLowerCase().split(" ");
    for (var a = 0; a < words.length; a++) {
        var w = words[a];
        words[a] = w[0].toUpperCase() + w.slice(1);
    }
    return words.join(" ");
}

The idea is to break the text into parts, and work each part separately. Breaking the text by spaces, you don’t have to worry about the specific treatment for this character.

If you want to include a hyphen or other character as a word separator, simply break the words inside the loop, or create a function to mount your array. Don’t forget to treat component merge later to reassemble the phrase as a string!

Answer 2

An alternative:

var teste = "this IS just A tExT";
teste = teste.toLowerCase().replace(/(?:^|\s)\S/g, function(a) {
  return a.toUpperCase();
});

console.log(teste);

Explanation:

First convert the whole word to Lower case, then through a regular expression get the first letter and all the letters that follow a blank space, replacing it with the respective uppercase letter.

The regular expression:

• ?: - Causes the expression between parentheses not to be memorized
• ^ - Match the first letter of the string
• | - Operator "or"
• \s - Make a blank
• \S - Match a character other than white space.

You can read more about regular expressions in Developer.mozilla.org

Answer 3

Another alternative, based on the famous map:

function titleize(string, separator = ' ') {
  return string
    .split(separator)
    .map((word) => word[0].toUpperCase() + word.slice(1).toLowerCase())
    .join(separator);
}

console.log(titleize('OLÁ como vAI?'));
console.log(titleize('hELLO wORLD!'));

The operation is simple:

A function is created that takes two arguments - the string to be formatted and a separator, which by default is a blank space. With this:

• Separate the received string with the separator;
• Iterate over each word (through the method Array.prototype.map), capitalizing on the first letter and turning the rest into lowercase;
• Merge all formatted words using the tab.

Answer 4

I made a small change in the code of the Colleague above, so that it does not give toUpperCase() in everything, like "Maria Da Silva E Melo", now stands Maria da Silva e Melo ....

function titleize(text) {
    var loweredText = text.toLowerCase();
    var words = loweredText.split(" ");
    for (var a = 0; a < words.length; a++) {
        var w = words[a];

        var firstLetter = w[0];
// aqui abaixo alterei 

        if( w.length > 2){ 
           w = firstLetter.toUpperCase() + w.slice(1);
        } else {
           w = firstLetter + w.slice(1);
        }

        words[a] = w;
    }
    return words.join(" ");
}

console.log (titleize("this IS just A tExT"));

Answer 5

In this solution it is good for proper names to avoid that prepositions become uppercase.

function processString(text) {
        let loweredText = text.toLowerCase();
        let wordsArray = loweredText.split(" ");

        let words = wordsArray.map((word)=> {
            let firstLetter = word[0];
            if( word.length > 2){
                return firstLetter.toUpperCase() + word.slice(1);
            } else {
                return firstLetter + word.slice(1);
            }
        });
        return words.join(" ");
    }
    processString('fuLanO De tAL');

Answer 6

function titleCase(str) {
 //pega apenas as palavras e tira todos os espaços em branco.
 return str.replace(/\w\S*/g, function(str) {

  //passa o primeiro caractere para maiusculo, e adiciona o todo resto minusculo
  return str.charAt(0).toUpperCase() + str.substr(1).toLowerCase();
 });
}

titleCase("testando a sTriNG");

Answer 7

I did so:

var titleize = (word) => {
  var newWord = [];
  var splited = word.split(" ");

  splited.forEach( word => {
    var firstLetter = word[0].toUpperCase();
    var restLetters = word.slice(1).toLowerCase();
    newWord.push(firstLetter+restLetters) 
  })

  return newWord.join(" ");
}

console.log(titleize("this IS just A tExT"));

I turned the string into an array with the method split and then I worked on each item of the array. It’s not as pretty when using regular expression, but it’s worth.

Answer 8

From to use a function this way with Javascript

function capitalize(str) {
  if (typeof str !== 'string') {
    return '';
  }

  return `${str.charAt(0).toUpperCase()}${str.substring(1).toLowerCase()}`;
}

or with Typescript

  export function capitalize(str: string) {
  if (typeof str !== 'string') {
    return '';
  }

  return `${str.charAt(0).toUpperCase()}${str.substring(1).toLowerCase()}`;
}