constructor is a function

4.5constructor/t3.js

@@ -0,0 +1,11 @@
+function Accumulator(startingValue){
+    this.value = startingValue;
+    this.read = function(){
+        new_value = +prompt("value?", 0);
+        this.value += new_value;
+    }
+}
+
+let accumulator = new Accumulator(1);
+accumulator.read();
+alert(accumulator.value);