javascript – How can I make the first letters of the words appear in capital letters?


The fact is that I have this code and it only converts me the first letter. The point is that I want to convert the first letters of each word and I don't know how to do it.

    document.write("Nombre y apellidos<input type='text' id='datos'><br>");
    document.write("<input type='button' value='Convertir' onclick='mostrarPalabra()'><br>");

    function mostrarPalabra() {
        var datos = document.getElementById('datos').value;
        datos = convertir(datos.toLowerCase());

    function convertir(string) {
        return string.charAt(0).toUpperCase() + string.slice(1);


The shortest implementation for capitalizing words within a string is as follows using the ES6 Arrow functions:

'your string'.replace(/\b\w/g, l => l.toUpperCase())
// => 'Your String'

ES5 compliant implementation:

'your string'.replace(/\b\w/g, function(l){ return l.toUpperCase() })
// => 'Your String'

The regular expression matches the first letter of each word within the given string and transforms only that letter to uppercase:

\ b matches a word boundary (the beginning or end of the word);
\ w matches the following metacharacters [a-zA-Z0-9].

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