update totalPrice() (change const to let & remove :void

src/app/p2/p2.component.ts

@@ -22,14 +22,14 @@ export class P2Component implements OnInit {
     message = '';
 
 
-    buildMessage(): void {
-    if (this.name !== null && this.price !== null && this.quantity !== null &&
-        this.name !== undefined && this.price !== undefined && this.quantity !== undefined
-      ) {
-        this.message = '你購買' + this.name + '商品，單價' + this.price + '元，數量'
-        + this.quantity + '元，共計NT$';
-        }
-    }
+    // buildMessage(): void {
+    // if (this.name !== null && this.price !== null && this.quantity !== null &&
+    //     this.name !== undefined && this.price !== undefined && this.quantity !== undefined
+    //   ) {
+    //     this.message = '你購買' + this.name + '商品，單價' + this.price + '元，數量'
+    //     + this.quantity + '元，共計NT$';
+    //     }
+    // }
 
     addData(): void {
 
@@ -48,10 +48,10 @@ export class P2Component implements OnInit {
 
   }
 
-    totalPrice(): void {
-      const result = 0;
+    totalPrice() {
+      let result = 0;
       for (
-        const i = 0; i < this.datas.length; i++
+        let i = 0; i < this.datas.length; i++
       ) { const data = this.datas[i];
         result = result + data.total;
       }