Merge pull request #125 from iamsoorena/JsonCleaner

adding function to clean json objects, deeply.

snippets/clean-json-objects.md

@@ -0,0 +1,21 @@
+### Clean Json objects
+
+Use `Object.keys()` method to loop over given json object and deleting keys that are not `include`d in given array.
+also if you give it a special key(`childIndicator`) it will search deeply inside it to apply function to inner objects too.
+
+```js
+const cleanObj = (obj, keysToKeep = [], childIndicator) => {
+  Object.keys(obj).forEach(key => {
+    if (key === childIndicator) {
+      cleanObj(obj[key], keysToKeep, childIndicator)
+    } else if (!keysToKeep.includes(key)) {
+      delete obj[key]
+    }
+  })
+}
+/*
+  testObj = {a: 1, b: 2, children: {a: 1, b: 2}}
+  cleanObj(testObj, ["a"],"children")
+  console.log(testObj)// { a: 1, children : { a: 1}}
+*/
+```