Javascript: Site Acronym for WordPress

site-acronym.js

// wrap the first word of the site title matching 'string' in a span to apply highlight color
	function siteAcronymClass(acronym) {

		var strTitle = document.getElementsByClassName('site-title')[0].innerHTML;

		var newStrTitle = strTitle.replace(acronym, '<span class="site-acronym">' + acronym + '</span>');

		if ( strTitle !== null ) {
			document.getElementsByClassName('site-branding-title')[0].innerHTML = newStrTitle;
		}
	}

	// Replace string value with acronym you want to wrap with a span class.
	siteAcronymClass('Acronym');
// end