Title case a sentence?

Question

I\'m trying to proper case a string in javascript - so far I have this code: This doesn\'t seem to capitalize the first letter, and I\'m also stuck on how to lowercase all the l

Answer 1

Here's a function titleCase(string, array) that transforms a string into title case, where the first letter of every word is capitalized except for certain prepositions, articles and conjunctions. If a word follows a colon, it will always be capitalized. You can include an optional array to ignore strings of your choice, such as acronyms.

I may have missed some exception words in the ignore array. Feel free to add them.

function titleCase(str, array){

  var arr = [];
  var ignore = ["a", "an", "and", "as", "at", "but", "by", "for", "from", "if", "in", "nor", "on", "of", "off", "or", "out", "over", "the", "to", "vs"];
  if (array) ignore = ignore.concat(array);
  ignore.forEach(function(d){
    ignore.push(sentenceCase(d));
  });

  var b = str.split(" ");

  return b.forEach(function(d, i){
    arr.push(ignore.indexOf(d) == -1 || b[i-1].endsWith(":") ? sentenceCase(d) : array.indexOf(d) != -1 ? d : d.toLowerCase());
  }), arr.join(" ");

  function sentenceCase(x){
    return x.toString().charAt(0).toUpperCase() + x.slice(x.length-(x.length-1));
  }

}

var x = titleCase("james comey to remain on as FBI director", ["FBI"]);
console.log(x); // James Comey to Remain on as FBI Director
var y = titleCase("maintaining substance data: an example");
console.log(y); // Maintaining Substance Data: An Example

Answer 2

I recently redid this problem using regex which matches the first letter and accounts for apostrophe. Hope it's helpful:

function titleCase(str) {

return str.toLowerCase().replace(/^\w|\s\w/g, function(firstLetter) {
    return firstLetter.toUpperCase();
  });
}
titleCase("I'm a little tea pot");

Answer 3

This should work. Notice how I set newstr[i] to the desired output. Functions like .toUpperCase() do not affect the original string. They only return a new string with the desired property.

function titleCase(str) {
  var newstr = str.split(" ");
  for(i=0;i<newstr.length;i++){
    if(newstr[i] == "") continue;
    var copy = newstr[i].substring(1).toLowerCase();
    newstr[i] = newstr[i][0].toUpperCase() + copy;
  }
   newstr = newstr.join(" ");
   return newstr;
}  

Answer 4

function capitalizeFirstLetter(string) {
    return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
}

This function uppercases 1st letter and lowercases the rest part od the string.

A bit changed function from the perfect answer found here: How do I make the first letter of a string uppercase in JavaScript?

Answer 5

const titleCase = str => {
    let string = str.toLowerCase().split(" ");
    let arr = [];
    
    string.map(x =>arr.push(x[0].toUpperCase() + x.slice(1))) 
    
    return arr.join(" ");
}

Answer 6

If you enjoy using Ramda like I do, you can do this clean fun thing:

import { concat, compose, head, join, map, split, tail, toLower, toUpper } from 'ramda';    
const toWords = split(' ');
const capitalizeWords = map(s => concat(toUpper(head(s)), toLower(tail(s))));
const toSentence = join(' ');
const toTitleCase = compose(toSentence, capitalizeWords, toWords);

or of course you can always cut it down to

const capitalizeWords = map(s => concat(toUpper(head(s)), toLower(tail(s))));
const toTitleCase = compose(join(' '), capitalizeWords, split(' '));