Show a specific router path via JavaScript (vue.js)

Question

I'm using vue.js 2 with routers. I want to show the user a other route URL with javascript alert message.

For example the user is on the route: /register, and i want to show you the link of /login. How can i do it?

<script>
export default {
    mounted() {            
        alert(this.$router.LINK_TO_PATH) //What comes here?
    },

}

Thanks