docs(modal): props default value

demo/documentation/components/modal/enUS/index.demo-entry.md

@@ -17,11 +17,11 @@ preset-confirm-slot
 |-|-|-|-|
 |display-directive|`'if' \| 'show'`|`'if'`|Use which directive to control the rendering of modal body.|
 |mask-closable|`boolean`|`true`|Whether to emit `hide` event when click mask.|
-|body-style|`Object`|`null`||
-|preset|`'card' \| 'confirm'`|`null`||
+|body-style|`Object`|`undefined`||
+|preset|`'card' \| 'confirm'`|`undefined`||
 |show|`boolean`|`false`|Whether to show modal.|
 |theme|`'light' \| 'dark' \| null \| string`|`null`||
-|on-update:show|`(value: boolean) => any`||Callback when modal's display status is changed.|
+|on-update:show|`(value: boolean) => any`|`undefined`|Callback when modal's display status is changed.|
 
 ### Modal with Preset Card
 See [Card props](n-card#Props)

demo/documentation/components/modal/zhCN/index.demo-entry.md

@@ -22,11 +22,11 @@ drawer-debug
 |-|-|-|-|
 |display-directive|`'if' \| 'show'`|`'if'`|使用何种指令控制模态框主体的条件渲染|
 |mask-closable|`boolean`|`true`|点击遮罩时是否发出 `update:show` 事件|
-|body-style|`Object \| null`|`null`||
-|preset|`'card' \| 'dialog' \| null`|`null`|模态框使用何种预设|
+|body-style|`Object`|`undefined`||
+|preset|`'card' \| 'dialog'`|`undefined`|模态框使用何种预设|
 |show|`boolean`|`false`|是否展示 Modal|
 |theme|`'light' \| 'dark' \| null \| string`|`null`||
-|on-update:show|`(value: boolean) => any`||模态框更新是否展示状态的回调|
+|on-update:show|`(value: boolean) => any`|`undefined`|模态框更新是否展示状态的回调|
 
 ### Modal（Card 预设）
 参考 [Card props](n-card#Props)

src/modal/src/BodyWrapper.vue

@@ -141,7 +141,7 @@ export default {
     },
     displayDirective: {
       type: String,
-      default: null
+      default: undefined
     },
     ...presetProps,
     // events

src/modal/src/Modal.js

@@ -33,7 +33,7 @@ export default {
     },
     preset: {
       type: String,
-      default: null
+      default: undefined
     },
     to: {
       type: [String, Object],

src/modal/src/presetProps.js

@@ -1,7 +1,7 @@
 export default {
   bodyStyle: {
     type: Object,
-    default: null
+    default: undefined
   },
   // For preset: confirm, card
   title: {