new exercise

Author: marianadacunha

record-collection-exercise.js

@@ -0,0 +1,51 @@
+// You are given a JSON object representing a part of your musical album collection. Each album has several properties and a unique 
+// id number as its key. Not all albums have complete information. Write a function which takes an album's id (like 2548), a property prop 
+// (like "artist" or "tracks"), and a value (like "Addicted to Love") to modify the data in this collection. If prop isn't "tracks" and 
+// value isn't empty (""), update or set the value for that record album's property. Your function must always return the entire collection 
+// object. There are several rules for handling incomplete data:
+
+// 1. If prop is "tracks" but the album doesn't have a "tracks" property, create an empty array before adding the new value to the 
+// album's corresponding property.
+
+// 2. If prop is "tracks" and value isn't empty (""), push the value onto the end of the album's existing tracks array.
+
+// 3. If value is empty (""), delete the given prop property from the album.
+
+var collection = {
+  2548: {
+    album: "Slippery When Wet",
+    artist: "Bon Jovi",
+    tracks: [
+      "Let It Rock",
+      "You Give Love a Bad Name"
+    ]
+  },
+  2468: {
+    album: "1999",
+    artist: "Prince",
+    tracks: [
+      "1999",
+      "Little Red Corvette"
+    ]
+  },
+  1245: {
+    artist: "Robert Palmer",
+    tracks: [ ]
+  },
+  5439: {
+    album: "ABBA Gold"
+  }
+};
+
+function updateRecords(id, prop, value) {
+  if(value === "") delete collection[id][prop];
+  else if(prop === "tracks") {
+    collection[id][prop] = collection[id][prop] || [];
+    collection[id][prop].push(value);
+  } else {
+    collection[id][prop] = value;
+  }
+  return collection;
+}
+
+updateRecords(5439, "artist", "ABBA");