<a href="#">Click me</a>

button:hover {
background-color: red;
}

function gotoPage(url) {
window.location.replace(url);
}

<button onclick="gotoPage('http://www.example.com')">Go to Example.com</button>

function gotoPage(url) {
window.location.href = url;
}

<button onclick="gotoPage('http://www.example.com')">Go to Example.com</button>