# How to Capitalize a Word in JavaScript

Back to another round of Pictorials, where we solve popular algorithm challenges step-by-step with tidbits. Today, let's learn how to capitalize a word!

Here are the 4 methods I'll be covering:

• toUpperCase()
• slice()
• charAt()
• toLowerCase()

☝️ Click more on the methods if you want to learn more. They're covered in my Web Basics series 👩🏻‍🏫

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# The Challenge

Write a function that capitalize a string.

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# 1. toLowerCase()

Unfortunately in JavaScript, there isn't a capitalize or title case a string. So what we can is utilize toLowerCase() to make the entire string lower-cased and then uppercase the first letter.

Convert the entire string to lower case.

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# 2. charAt()

Let's access the first letter of our string so we can uppercase it later.

Get the first character of the string

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# 3. toUpperCase()

Great! Now we can uppercase that first letter.

Transform the first character to upper case

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# 4. slice()

So there's 2 part of our string to complete our capitalization. The first letter which has been upper-cased and we got that with charAt(). Next we need the rest of our letters. And we can extract using .slice().

Extract the entire string except the first letter

# 3. +

Alright, we have all the pieces. Next, we need to put it together. We can use our + operator to combine strings.

Combine the strings

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# Final Solution

Awesome! We have successfully capitalize our string 🥳

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# More Solutions

Using charAt

function capitalize(word) {
  const lower = str.toLowerCase();
  return str.charAt(0).toUpperCase() + lower.slice(1);
}

Using Bracket Notation

function capitalize(word) {
  return word[0].toUpperCase() + word.slice(1).toLowerCase();
}

Using substring

function capitalize(word) {
  return word[0].toUpperCase() + word.substring(1).toLowerCase();
}

Using 2 steps

function capitalize(word) {
  const loweredCase = word.toLowerCase();
  return word[0].toUpperCase() + loweredCase.slice(1);
}

Using Rest parameter

function capitalize([first, ...rest]) {
  return first.toUpperCase() + rest.join('').toLowerCase();
}

Using Map

function capitalize(word) {
  return word
    .split('')
    .map((letter, index) =>
      index ? letter.toLowerCase() : letter.toUpperCase(),
    )
    .join('');
}

Using Regex

function capitalize(word) {
  return word
    .toLowerCase()
    .replace(/\w/, firstLetter => firstLetter.toUpperCase());
}