Done

index.js

@@ -0,0 +1,23 @@
+var obj = {}
+
+function updateObjectWithKeyAndValue(obj, key, value){
+  return Object.assign ({}, obj, {[key] : value})
+}
+
+function destructivelyUpdateObjectWithKeyAndValue(obj, key, value){
+  obj.prop2 = 2
+  return obj
+}
+
+function deleteFromObjectByKey(obj, key){
+  var obj = { prop: 1 }
+  var newObj = Object.assign({}, obj)
+  delete newObj.prop
+  return newObj
+  return obj
+}
+
+function destructivelyDeleteFromObjectByKey(obj, key){
+  delete obj.prop
+  return obj
+}