Capitalize the First Letter of a String in JavaScript

Jul 24, 2019

JavaScript doesn't have a built-in function to convert the first letter of a string to uppercase. However, you can capitalize the first letter of a string with one line of vanilla JS. You can also use lodash or CSS. In this tutorial, you'll learn to use all 3.

Using Vanilla JS

JavaScript has a String#uppercase() function that converts an entire string to uppercase. That means you can capitalize the first character and combine it with the substring containing everything but the first character.

function capitalize(str) {
  return str.charAt(0).toUpperCase() + str.slice(1);
}

capitalize('dog'); // 'Dog'
capitalize('cAT'); // 'CAT'

Using Lodash

Lodash's capitalize() function also capitalizes the first character in a string. It also converts the remaining characters to lowercase.

const _ = require('lodash');

_.capitalize('dog'); // 'Dog'
_.capitalize('cAT'); // 'Cat'

Using CSS

Depending on your use case, you might not need JavaScript at all. CSS text-transform: capitalize capitalizes the first letter of each word in the string.

.capitalize {
  text-transform: capitalize;
}

So given the string 'capitalize using CSS', the browser will render the string as 'capitalize using CSS'.


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