diff --git a/src/Common/Singleton.ts b/src/Common/Singleton.ts
index 5e1d4e2d2..8f4b8f9ff 100644
--- a/src/Common/Singleton.ts
+++ b/src/Common/Singleton.ts
@@ -25,13 +25,13 @@ export class Singleton
      */
     static GetInstance<T>(Class: { new(): T; }): T
     {
-        let obj = this.singletonMap.get(Class);
-        if (!obj)
+        let instance = this.singletonMap.get(Class);
+        if (!instance)
         {
-            obj = new Class();
-            this.singletonMap.set(Class, obj);
+            instance = new Class();
+            this.singletonMap.set(Class, instance);
         }
-        return obj;
+        return instance;
     }
 
     /**
diff --git a/src/DatabaseServices/Arc.ts b/src/DatabaseServices/Arc.ts
index 45792a011..380c80b5b 100644
--- a/src/DatabaseServices/Arc.ts
+++ b/src/DatabaseServices/Arc.ts
@@ -615,9 +615,9 @@ export class Arc extends Curve
                 let pts = [this.StartPoint, this.EndPoint];
                 let [sp, ep] = pts;
 
-                let OldChordLengthHalf = sp.distanceTo(ep) * 0.5;
+                let oldChordLengthHalf = sp.distanceTo(ep) * 0.5;
 
-                let arcHeight = OldChordLengthHalf * this.Bul;
+                let arcHeight = oldChordLengthHalf * this.Bul;
 
                 pts[index].add(vec);
 
diff --git a/src/DatabaseServices/Polyline.ts b/src/DatabaseServices/Polyline.ts
index 58f5a4e1d..44a32ca26 100644
--- a/src/DatabaseServices/Polyline.ts
+++ b/src/DatabaseServices/Polyline.ts
@@ -1042,14 +1042,14 @@ export class Polyline extends Curve
                     let notChangeP = this.GetPointAtParam(nextIndex);
 
                     //原先的弦长的一半
-                    let OldChordLengthHalf = needChangeP.distanceTo(notChangeP) * 0.5;
+                    let oldChordLengthHalf = needChangeP.distanceTo(notChangeP) * 0.5;
 
                     //弓高
-                    let arcHeight = OldChordLengthHalf * d.bul;
+                    let arcHeight = oldChordLengthHalf * d.bul;
 
                     needChangeP.add(vec);
 
-                    let newChordLengthHalf = (needChangeP.distanceTo(notChangeP) * 0.5);
+                    let newChordLengthHalf = needChangeP.distanceTo(notChangeP) * 0.5;
 
                     d.bul = arcHeight / newChordLengthHalf;
                 }