修复选项清空bug

source/vue/xzs-admin/package-lock.json

@@ -4465,9 +4465,9 @@
             }
         },
         "core-js": {
-            "version": "3.8.3",
-            "resolved": "https://registry.npm.taobao.org/core-js/download/core-js-3.8.3.tgz?cache=0&sync_timestamp=1611040756909&other_urls=https%3A%2F%2Fregistry.npm.taobao.org%2Fcore-js%2Fdownload%2Fcore-js-3.8.3.tgz",
-            "integrity": "sha1-whkG4fFPNon5OrzG4miDVQ3ZLdA="
+            "version": "3.9.0",
+            "resolved": "https://registry.npm.taobao.org/core-js/download/core-js-3.9.0.tgz?cache=0&sync_timestamp=1613668840564&other_urls=https%3A%2F%2Fregistry.npm.taobao.org%2Fcore-js%2Fdownload%2Fcore-js-3.9.0.tgz",
+            "integrity": "sha1-eQsbsRVToicrNuJiXHF52zRUkvg="
         },
         "core-js-compat": {
             "version": "3.8.3",

source/vue/xzs-admin/package.json

@@ -16,7 +16,7 @@
     },
     "dependencies": {
         "axios": "^0.19.0",
-        "core-js": "^3.8.3",
+        "core-js": "^3.9.0",
         "element-ui": "^2.15.0",
         "js-cookie": "2.2.0",
         "normalize.css": "8.0.1",

source/vue/xzs-admin/src/views/exam/question/edit/single-choice.vue

@@ -157,8 +157,13 @@ export default {
     },
     questionItemAdd () {
       let items = this.form.items
-      let last = items[items.length - 1]
-      let newLastPrefix = String.fromCharCode(last.prefix.charCodeAt() + 1)
+      let newLastPrefix
+      if (items.length > 0) {
+        let last = items[items.length - 1]
+        newLastPrefix = String.fromCharCode(last.prefix.charCodeAt() + 1)
+      } else {
+        newLastPrefix = 'A'
+      }
       items.push({ id: null, prefix: newLastPrefix, content: '' })
     },
     submitForm () {

source/xzs/src/main/resources/static/admin/index.html

@@ -13,4 +13,4 @@
       hm.src = 'https://hm.baidu.com/hm.js?cd8218cd51f800ed2b73e5751cb3f4f9'
       var s = document.getElementsByTagName('script')[0]
       s.parentNode.insertBefore(hm, s)
-    })()</script><link href="static/css/chunk-066bbd34.c306629d.css" rel="prefetch"><link href="static/css/chunk-111f3671.d650a2aa.css" rel="prefetch"><link href="static/css/chunk-157f9069.c306629d.css" rel="prefetch"><link href="static/css/chunk-19291efa.c306629d.css" rel="prefetch"><link href="static/css/chunk-2e16d177.89936c18.css" rel="prefetch"><link href="static/css/chunk-360c43ba.c306629d.css" rel="prefetch"><link href="static/css/chunk-3f483335.7fbe318e.css" rel="prefetch"><link href="static/css/chunk-42236473.c306629d.css" rel="prefetch"><link href="static/css/chunk-5bc3d75d.c306629d.css" rel="prefetch"><link href="static/css/chunk-65f8ca6f.c306629d.css" rel="prefetch"><link href="static/css/chunk-7c62808c.c306629d.css" rel="prefetch"><link href="static/css/chunk-873a42e2.1951fa25.css" rel="prefetch"><link href="static/css/chunk-a85d3c1e.c8588555.css" rel="prefetch"><link href="static/css/chunk-a9d03770.c306629d.css" rel="prefetch"><link href="static/css/chunk-bab2e2c4.c306629d.css" rel="prefetch"><link href="static/js/chunk-066bbd34.3194df9d.js" rel="prefetch"><link href="static/js/chunk-111f3671.92b6a5d2.js" rel="prefetch"><link href="static/js/chunk-157f9069.85f4f4a4.js" rel="prefetch"><link href="static/js/chunk-16f9edc1.50c690ca.js" rel="prefetch"><link href="static/js/chunk-19291efa.4e5bd268.js" rel="prefetch"><link href="static/js/chunk-2d0c138b.d639e644.js" rel="prefetch"><link href="static/js/chunk-2d221bd2.79734f7b.js" rel="prefetch"><link href="static/js/chunk-2d2300ef.06454c78.js" rel="prefetch"><link href="static/js/chunk-2d230fe7.3bd3f709.js" rel="prefetch"><link href="static/js/chunk-2e16d177.a52bb75e.js" rel="prefetch"><link href="static/js/chunk-360c43ba.43f3f2df.js" rel="prefetch"><link href="static/js/chunk-3f483335.9805b6d5.js" rel="prefetch"><link href="static/js/chunk-42236473.b06437f4.js" rel="prefetch"><link href="static/js/chunk-5bc3d75d.16fd0651.js" rel="prefetch"><link href="static/js/chunk-65f8ca6f.cc68113a.js" rel="prefetch"><link href="static/js/chunk-733c35b2.7c9953cf.js" rel="prefetch"><link href="static/js/chunk-75f11c77.e5a5c7ca.js" rel="prefetch"><link href="static/js/chunk-78234ca2.a1ececd4.js" rel="prefetch"><link href="static/js/chunk-793f0082.b6b96c49.js" rel="prefetch"><link href="static/js/chunk-7c62808c.558ddec6.js" rel="prefetch"><link href="static/js/chunk-873a42e2.c668a1e2.js" rel="prefetch"><link href="static/js/chunk-a85d3c1e.c9dd4754.js" rel="prefetch"><link href="static/js/chunk-a9d03770.e66ccc01.js" rel="prefetch"><link href="static/js/chunk-bab2e2c4.5bb927b4.js" rel="prefetch"><link href="static/js/chunk-d0753fda.6c67deb1.js" rel="prefetch"><link href="static/css/chunk-vendors.ee57d822.css" rel="preload" as="style"><link href="static/css/index.9dc49bd0.css" rel="preload" as="style"><link href="static/js/chunk-vendors.d6404b06.js" rel="preload" as="script"><link href="static/js/index.96c6a59d.js" rel="preload" as="script"><link href="static/css/chunk-vendors.ee57d822.css" rel="stylesheet"><link href="static/css/index.9dc49bd0.css" rel="stylesheet"></head><body><noscript><strong>We're sorry but vue-demo doesn't work properly without JavaScript enabled. Please enable it to continue.</strong></noscript><div id="app"></div><script src="static/js/chunk-vendors.d6404b06.js"></script><script src="static/js/index.96c6a59d.js"></script></body></html>
+    })()</script><link href="static/css/chunk-066bbd34.c306629d.css" rel="prefetch"><link href="static/css/chunk-111f3671.d650a2aa.css" rel="prefetch"><link href="static/css/chunk-157f9069.c306629d.css" rel="prefetch"><link href="static/css/chunk-19291efa.c306629d.css" rel="prefetch"><link href="static/css/chunk-2e16d177.89936c18.css" rel="prefetch"><link href="static/css/chunk-360c43ba.c306629d.css" rel="prefetch"><link href="static/css/chunk-3f483335.7fbe318e.css" rel="prefetch"><link href="static/css/chunk-42236473.c306629d.css" rel="prefetch"><link href="static/css/chunk-5bc3d75d.c306629d.css" rel="prefetch"><link href="static/css/chunk-65f8ca6f.c306629d.css" rel="prefetch"><link href="static/css/chunk-7c62808c.c306629d.css" rel="prefetch"><link href="static/css/chunk-873a42e2.1951fa25.css" rel="prefetch"><link href="static/css/chunk-a85d3c1e.c8588555.css" rel="prefetch"><link href="static/css/chunk-a9d03770.c306629d.css" rel="prefetch"><link href="static/css/chunk-bab2e2c4.c306629d.css" rel="prefetch"><link href="static/js/chunk-066bbd34.92d70152.js" rel="prefetch"><link href="static/js/chunk-111f3671.084f20c2.js" rel="prefetch"><link href="static/js/chunk-157f9069.2f17516e.js" rel="prefetch"><link href="static/js/chunk-16f9edc1.45181ec9.js" rel="prefetch"><link href="static/js/chunk-19291efa.3c0f8731.js" rel="prefetch"><link href="static/js/chunk-2d0c138b.da9cc8ab.js" rel="prefetch"><link href="static/js/chunk-2d221bd2.04cd3c6f.js" rel="prefetch"><link href="static/js/chunk-2d2300ef.e813a70e.js" rel="prefetch"><link href="static/js/chunk-2d230fe7.3bd3f709.js" rel="prefetch"><link href="static/js/chunk-2e16d177.0fcc426b.js" rel="prefetch"><link href="static/js/chunk-360c43ba.b492fe84.js" rel="prefetch"><link href="static/js/chunk-3f483335.f703fcab.js" rel="prefetch"><link href="static/js/chunk-42236473.b0f02a56.js" rel="prefetch"><link href="static/js/chunk-5bc3d75d.0ff9b74a.js" rel="prefetch"><link href="static/js/chunk-65f8ca6f.4da009d5.js" rel="prefetch"><link href="static/js/chunk-733c35b2.c975cd57.js" rel="prefetch"><link href="static/js/chunk-75f11c77.dc7770a3.js" rel="prefetch"><link href="static/js/chunk-78234ca2.bbac33f4.js" rel="prefetch"><link href="static/js/chunk-793f0082.e5a781a8.js" rel="prefetch"><link href="static/js/chunk-7c62808c.20394c5b.js" rel="prefetch"><link href="static/js/chunk-873a42e2.10973ce2.js" rel="prefetch"><link href="static/js/chunk-a85d3c1e.0c208b6b.js" rel="prefetch"><link href="static/js/chunk-a9d03770.67c584cb.js" rel="prefetch"><link href="static/js/chunk-bab2e2c4.c8022dac.js" rel="prefetch"><link href="static/js/chunk-d0753fda.82934df5.js" rel="prefetch"><link href="static/css/chunk-vendors.ee57d822.css" rel="preload" as="style"><link href="static/css/index.9dc49bd0.css" rel="preload" as="style"><link href="static/js/chunk-vendors.6ba47d39.js" rel="preload" as="script"><link href="static/js/index.65137ee8.js" rel="preload" as="script"><link href="static/css/chunk-vendors.ee57d822.css" rel="stylesheet"><link href="static/css/index.9dc49bd0.css" rel="stylesheet"></head><body><noscript><strong>We're sorry but vue-demo doesn't work properly without JavaScript enabled. Please enable it to continue.</strong></noscript><div id="app"></div><script src="static/js/chunk-vendors.6ba47d39.js"></script><script src="static/js/index.65137ee8.js"></script></body></html>