u

coretool.js

@@ -246,7 +246,7 @@ module.exports = {
       : t // 可以是 undefined, boolean, number, string
   },
 
-  read_varchain (path, root) {
+  read_varchain (path, root, emptyValue) {
     let parent = root || globalThis || global || window || {}
     let keychain = path.split('.')
     for (let key of keychain) {
@@ -258,13 +258,13 @@ module.exports = {
         // 支持 myarr[index] 作为一个路径节点
         let [all, arr, index] = key.match(/^(\w+)\[(.*)\]$/)
         parent = parent[arr][parseInt(index)]
-      } else if (typeof parent === 'object' && /^\w+$/.test(key) && typeof parent[key] != 'undefined' && parent[key] != null) {
+      } else if (typeof parent === 'object' && /^\w+$/.test(key) && typeof parent[key] != 'undefined') {
         parent = parent[key]
       } else {
-        return undefined
+        return emptyValue
       }
     }
-    return parent
+    return typeof parent !== 'undefined' ? parent : emptyValue
   },
 
   set_varchain (path, root, value) {
@@ -298,6 +298,9 @@ module.exports = {
   },
 
   number_precision (number, precision = 4) {
+    if (isFinite(number)) // null, '', '0', [] 
       return Number(Number(number).toFixed(precision))
+    else // undefined, NaN, Infinity, {}
+      return 0
   },
 }