diff --git a/helpers/dataFilter.js b/helpers/dataFilter.js
index ede3a61..82eae31 100644
--- a/helpers/dataFilter.js
+++ b/helpers/dataFilter.js
@@ -1,7 +1,12 @@
+const log = require("../utils/log");
 const getAllData = require("./getAllData")
 
 function dataFilter(arrayName, condition) {
     const dataAll = getAllData();
+    if (dataAll[arrayName] == undefined) {
+        log(`${arrayName} array not found.`, "Error", "error");
+        return undefined
+    }
     return dataAll[arrayName].filter(condition)
 }
 
diff --git a/helpers/dataFind.js b/helpers/dataFind.js
index 7246520..6083257 100644
--- a/helpers/dataFind.js
+++ b/helpers/dataFind.js
@@ -1,7 +1,12 @@
+const log = require("../utils/log");
 const getAllData = require("./getAllData")
 
 function dataFind(arrayName, condition) {
     const dataAll = getAllData();
+    if (dataAll[arrayName] == undefined) {
+        log(`${arrayName} array not found.`, "Error", "error");
+        return undefined
+    }
     return dataAll[arrayName].find(condition)
 }
 
diff --git a/helpers/removeData.js b/helpers/removeData.js
index b0a2458..1993b8b 100644
--- a/helpers/removeData.js
+++ b/helpers/removeData.js
@@ -1,8 +1,13 @@
 const getAllData = require("./getAllData");
 const writeDataJson = require("./writeDataJson");
+const log = require("../utils/log");
 
 function removeData(arrayName, dataId) {
     var dataAll = getAllData();
+    if (dataAll[arrayName] == undefined) {
+        log(`${arrayName} array not found.`, "Error", "error");
+        return undefined
+    }
     const index = dataAll[arrayName].findIndex(x => x.id == dataId);
     dataAll[arrayName].splice(index, 1);
     writeDataJson(JSON.stringify(dataAll));
diff --git a/helpers/updateData.js b/helpers/updateData.js
index 222d855..4972ce8 100644
--- a/helpers/updateData.js
+++ b/helpers/updateData.js
@@ -1,16 +1,34 @@
 const getAllData = require("./getAllData");
 const writeDataJson = require("./writeDataJson");
+const log = require("../utils/log");
 
 function updateData(arrayName, data) {
     var dataAll = getAllData();
+
+    if (dataAll[arrayName] == undefined) {
+        log(`${arrayName} array not found.`, "Error", "error");
+        return undefined
+    }
+
+    if (!data.id) {
+        log(`There is no id data!`, "Error", "error");
+        return undefined
+    }
+
     const index = dataAll[arrayName].findIndex(i => i.id === data.id);
+
+    if (index == -1) {
+        log(`No data matching id found!`, "Error", "error");
+        return undefined
+    }
+
     Object.entries(dataAll[arrayName][index]).forEach(entry => {
         const [key, value] = entry;
         if (key != "id") {
             dataAll[arrayName][index][key] = data[key];
         }
     });
-    writeDataJson(JSON.stringify(dataAll));
+    writeDataJson(JSON.stringify(dataAll, null, 4));
 }
 
 module.exports = updateData;
\ No newline at end of file
diff --git a/operations/add.js b/operations/add.js
index 6c2f3ec..875eb79 100644
--- a/operations/add.js
+++ b/operations/add.js
@@ -16,6 +16,7 @@ function add(arrayName, data) {
         newData[arrayName].push(data);
     }
     writeDataJson(JSON.stringify(newData, null, 4));
+    return data;
 }
 
 module.exports = add;
\ No newline at end of file
diff --git a/operations/data/db.json b/operations/data/db.json
new file mode 100644
index 0000000..aa0d905
--- /dev/null
+++ b/operations/data/db.json
@@ -0,0 +1,12 @@
+{
+        "products": [
+            {
+                "id": 1,
+                "categoryId": 2,
+                "productName": "Chai",
+                "quantityPerUnit": "48 - 6 oz jars",
+                "unitPrice": "30",
+                "unitsInStock": 53
+            }
+        ]
+    }
\ No newline at end of file
diff --git a/operations/getById.js b/operations/getById.js
index b6b8a3d..f6a7330 100644
--- a/operations/getById.js
+++ b/operations/getById.js
@@ -1,7 +1,12 @@
 const getAll = require("./getAll");
+const log = require('../utils/log');
 
 function getById(arrayName, dataId) {
     var dataAll = getAll();
+    if (dataAll[arrayName] == undefined) {
+        log(`${arrayName} array not found.`, "Error", "error");
+        return undefined
+    }
     return dataAll[arrayName].find(x => x.id == dataId)
 }
 
diff --git a/package.json b/package.json
index b7eb83c..1d02f01 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
 	"name": "dbcopycat",
-	"version": "0.4.1",
+	"version": "0.5.1",
 	"description": "A JSON Database that saves your Json data in a file and makes it easy for you to perform CRUD operations.",
 	"main": "local.js",
 	"license": "ISC",