no message

+#### Distinguish helper
+
+###### *mapState*
+
+> 读取state中的值进行操作, 不对 state本身进行计算.
+
+```javascript
+// 单独计算
+computed: mapState({
+  count: state => state.count,
+  countAlias: 'count', // 别名
+  countPlusLocalState (state) {
+    return state.count + this.localCount // 结合本地值进行计算
+  }
+})
+// 计算属性名称 === 状态子树名称
+computed: mapState([
+  'count'
+])
+// 混合计算
+computed: {
+  localComputed () { /* ... */},
+  ...mapState({
+    count: state => state.count,
+    countAlias: 'count', // 别名
+    countPlusLocalState (state) {
+      return state.count + this.localCount // 结合本地值进行计算
+    }
+  })
+}
+```
+
+###### mapGetters
+
+> 混合计算时:使用*对象扩展操作符*, 名称相同时传入同名数组, 映射不同名称时, 传入对象键值对, 键值对可以操作参考上面示例混合计算.
+
+```javascript
+// 混合计算
+computed: {
+  localComputed () { /* ... */},
+  ...mapGetters([
+    'doneTodosCount',
+    'anotherGetter'
+  ])
+}
+// 映射不同名称
+mapGetters({
+  doneCount: 'doneTodosCount'
+})
+```
+
+##### Mutations
+
+###### Payload
+
+```javascript
+mutations: {
+  increment (state, payload) {
+    state.count += payload.amount
+  }
+}
+```
+
+```javascript
+//
+store.commit('increment', {
+  amount: 10
+})
+// 对象风格
+store.commit({
+  type: 'increment',
+  amount: 10
+})
+```
+
+###### mapMutations
+
+```javascript
+methods: {
+  ...mapMutations([
+    'increment' // 映射 this.increment 到 this.$store.commit('increment')
+  ]),
+  ...mapMutations({
+    add: 'increment' // 映射 this.add 到 this.$store.commit('increment')
+  })
+}
+```
+
+###### Const Named Mutation
+
+```javascript
+// mutation-types.js
+export const SOME_MUTATION = 'SOME_MUTATION'
+```
+
+```javascript
+// store.js
+import { SOME_MUTATION } from './mutation-types'
+mutations: {
+  [SOME_MUTATION] (state) {
+    // change state
+  }
+}
+```
+

@@ -8,9 +8,7 @@
 </template>
 
 <script>
-import {
-    mapState
-} from 'vuex'
+import { mapState } from 'vuex'
 
 export default {
     data() {