vueが定義するプライベートフィルタと基本的な使い方

<script>
        let vm = new Vue({
            el:'#app',
            data:{
            
            },
            filters: { // filters that are private to the current instance

            }
        })
    </script>

    <div id="app">
        <p>{{mes | addStr}}</p>
    </div>

    <script src=". /js/vue.js"></script>
    <script>
        let vm = new Vue({
            el:'#app',
            data:{
                mes:"I'm a pessimist, pessimists do pessimistic things"
            },
            filters: { // filters that are private to the current instance
                addStr(data,str="happy"){
                    return data.replace(/pessimistic/g,str)
                }
            }
        })
    </script>

<div id="app">
        <p>{{mes | setStr | addStr}}</p>
    </div>

    <script src=". /js/vue.js"></script>
    <script>

        Vue.filter('setStr',function(data){
            return data+'I am a global filter'
        })

        let vm = new Vue({
            el:'#app',
            data:{
                mes:"I'm a pessimist, pessimists do pessimistic things"
            },
            filters: { // filters that are private to the current instance
                addStr(data,str="happy"){
                    return data.replace(/pessimistic/g,str)
                }
            }
        })
    </script>