doc文档示例代码整改

Change-Id: I575b55db46ebae64b56392192773eab0ff73ce08
Signed-off-by: Nzhengjiangliang <zhengjiangliang@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-display.md

@@ -94,7 +94,7 @@ try {
     displayClass = display.getDefaultDisplaySync();
 } catch (exception) {
     console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
-};
+}
 ```
 
 ## display.getAllDisplays<sup>9+</sup>
@@ -204,25 +204,24 @@ hasPrivateWindow(displayId: number): boolean
 let displayClass = null;
 try {
     displayClass = display.getDefaultDisplaySync();
-} catch (exception) {
-    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
-    return;
-};
 
-let ret = undefined;
-try {
+    let ret = undefined;
+    try {
         ret = display.hasPrivateWindow(displayClass.id);
-} catch (exception) {
+    } catch (exception) {
         console.error('Failed to check has privateWindow or not. Code: ' + JSON.stringify(exception));
-};
-if (ret == undefined) {
+    }
+    if (ret == undefined) {
         console.log("Failed to check has privateWindow or not.");
-}
-if (ret) {
+    }
+    if (ret) {
         console.log("There has privateWindow.");
-} else if (!ret) {
+    } else if (!ret) {
         console.log("There has no privateWindow.");
-};
+    }
+} catch (exception) {
+    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
+}
 ```
 
 ## display.on('add'|'remove'|'change')
@@ -250,7 +249,7 @@ try {
     display.on("add", callback);
 } catch (exception) {
     console.error('Failed to register callback. Code: ' + JSON.stringify(exception));
-};
+}
 ```
 
 ## display.off('add'|'remove'|'change')
@@ -275,7 +274,7 @@ try {
     display.off("remove");
 } catch (exception) {
     console.error('Failed to unregister callback. Code: ' + JSON.stringify(exception));
-};
+}
 ```
 
 ## display.getDefaultDisplay<sup>(deprecated)</sup>
@@ -450,17 +449,17 @@ getCutoutInfo(callback: AsyncCallback&lt;CutoutInfo&gt;): void
 let displayClass = null;
 try {
     displayClass = display.getDefaultDisplaySync();
-} catch (exception) {
-    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
-};
 
-displayClass.getCutoutInfo((err, data) => {
+    displayClass.getCutoutInfo((err, data) => {
         if (err.code) {
             console.error('Failed to get cutoutInfo. Code: ' + JSON.stringify(err));
             return;
         }
         console.info('Succeeded in getting cutoutInfo. data: ' + JSON.stringify(data));
-});
+    });
+} catch (exception) {
+    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
+}
 ```
 ### getCutoutInfo<sup>9+</sup>
 getCutoutInfo(): Promise&lt;CutoutInfo&gt;
@@ -489,12 +488,14 @@ getCutoutInfo(): Promise&lt;CutoutInfo&gt;
 let displayClass = null;
 try {
     displayClass = display.getDefaultDisplaySync();
-} catch (exception) {
-    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
-};
 
-let promise = displayClass.getCutoutInfo();
-promise.then((data) => {
+    let promise = displayClass.getCutoutInfo();
+    promise.then((data) => {
         console.info('Succeeded in getting cutoutInfo. Data: ' + JSON.stringify(data));
-});
+    }).catch((err) => {
+        console.error('Failed to obtain all the display objects. Code: ' + JSON.stringify(err));
+    });
+} catch (exception) {
+    console.error('Failed to obtain the default display object. Code: ' + JSON.stringify(exception));
+}
 ```