Javascript capitilizing first letter in each word in a string

Question

I have a function that should capitalize every first letter in each word in a string, but somehow it delivers incorrect result, any idea why? I need to fix it a bit.

So the input: hello dolly output: Hello Dolly.

Spaces are correctly counted but the capitalization is incorrect.

function letterCapitalize(str) {
  str = str.replace(str.charAt(0), str.charAt(0).toUpperCase());
  let spaces = [];
  for (let i = 0; i < str.length; i++) {
    if (str[i] === ' ') spaces.push(i);
  }
  for (let space of spaces) {
    str = str.replace(str.charAt(space + 1), str.charAt(space + 1).toUpperCase());
  }
  return str;
}

console.log(letterCapitalize("hello there, how are you?"));

I am aware that replace replaces just the first occurance, but how should I make work it properly? — Z. Bird, Oct 26 '19 at 16:47
What's the difference between your function and `.toUpperCase()`? — Ori Drori, Oct 26 '19 at 16:50
`const letterCapitalize = x => x.replace(/[a-zA-Z]/g, l => l.toUpperCase())` — Tibike, Oct 26 '19 at 16:51
@Tibike no need of A-Z inside character class, as OP is trying to change to uppercase, so /[a-z]/ will be enough — Code Maniac, Oct 26 '19 at 16:58
@ASDFGerte toUpperCase converts all to uppercase, I need just the first letter so from hi dolly => Hi Dolly — Z. Bird, Oct 26 '19 at 17:28
"should capitalize every letter in string" - from your own question. — ASDFGerte, Oct 26 '19 at 17:29
@ASDFGerte I edited my question, cuz I noticed the word first somehow got out — Z. Bird, Oct 26 '19 at 17:37

score 1 · Accepted Answer · edited Oct 26 '19 at 17:21

1

// Option One

function capitalize1( str ) {
  let result = str[ 0 ].toUpperCase();

  for ( let i = 1; i < str.length; i++ ) {
    if ( str[ i - 1 ] === ' ' ) {
      result += str[ i ].toUpperCase();
    } else {
      result += str[ i ];
    }
  }

  return result;
}

// Option Two

function capitalize2(str) {
  const words = [];

  for (let word of str.split(' ')) {
    words.push(word[0].toUpperCase() + word.slice(1));
  }

  return words.join(' ');
}

console.log(capitalize1('hello there, how are you?'))
console.log(capitalize2('hello there, how are you?'))

edited Oct 26 '19 at 17:21

mplungjan

169,008
28
173
236

answered Oct 26 '19 at 16:53

SakoBu

3,972
1
16
33

YEY! thats it man, thats exactly what I needed... idk why I wanted to use replace for all cost, this is more simple. Thanks @mplungjan – Z. Bird Oct 26 '19 at 17:34
and also thank you @SakoBu – Z. Bird Oct 26 '19 at 17:35

Tibike · Answer 2 · 2019-10-26T17:22:02.070

0

You could use string.toUpperCase() or if you require more specific logic you could use string.replace() with some regular expression

const letterCapitalize = x => x.toUpperCase();

const letterCapitalizeWithRegex = x => x.replace(/[a-z]/g, l => l.toUpperCase());

console.log("my string".toUpperCase());

console.log(letterCapitalize("my string"));

console.log(letterCapitalizeWithRegex("my string"));

edited Oct 26 '19 at 17:22

answered Oct 26 '19 at 16:59

Tibike

338
2
12

The question was adjusted, I need just every first letter of the string, not all characters – Z. Bird Oct 26 '19 at 17:32

Javascript capitilizing first letter in each word in a string

2 Answers2