diff --git a/doc/examples/addressbook-sdk/part2/addressbook.cpp b/doc/examples/addressbook-sdk/part2/addressbook.cpp
index 8d65858e16d..7399b938138 100644
--- a/doc/examples/addressbook-sdk/part2/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part2/addressbook.cpp
@@ -95,7 +95,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
         return;
diff --git a/doc/examples/addressbook-sdk/part3/addressbook.cpp b/doc/examples/addressbook-sdk/part3/addressbook.cpp
index d96e22c2e2b..08e786fd783 100644
--- a/doc/examples/addressbook-sdk/part3/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part3/addressbook.cpp
@@ -102,7 +102,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
         return;
diff --git a/doc/examples/addressbook-sdk/part4/addressbook.cpp b/doc/examples/addressbook-sdk/part4/addressbook.cpp
index 8ed395b9bf3..707946ea3a7 100644
--- a/doc/examples/addressbook-sdk/part4/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part4/addressbook.cpp
@@ -101,7 +101,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
     }
diff --git a/doc/examples/addressbook-sdk/part5/addressbook.cpp b/doc/examples/addressbook-sdk/part5/addressbook.cpp
index 32cbeaf7cee..916f6a153bc 100644
--- a/doc/examples/addressbook-sdk/part5/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part5/addressbook.cpp
@@ -96,7 +96,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
         updateInterface(NavigationMode);
diff --git a/doc/examples/addressbook-sdk/part6/addressbook.cpp b/doc/examples/addressbook-sdk/part6/addressbook.cpp
index aacf0f24883..e56caf35380 100644
--- a/doc/examples/addressbook-sdk/part6/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part6/addressbook.cpp
@@ -102,7 +102,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
         updateInterface(NavigationMode);
diff --git a/doc/examples/addressbook-sdk/part7/addressbook.cpp b/doc/examples/addressbook-sdk/part7/addressbook.cpp
index 10a4aef0a19..980535c52ad 100644
--- a/doc/examples/addressbook-sdk/part7/addressbook.cpp
+++ b/doc/examples/addressbook-sdk/part7/addressbook.cpp
@@ -99,7 +99,7 @@ void AddressBook::submitContact()
     QString name = ui->nameLine->text();
     QString address = ui->addressText->toPlainText();
 
-    if (name == "" || address == "") {
+    if (name.isEmpty() || address.isEmpty()) {
         QMessageBox::information(this, tr("Empty Field"),
             tr("Please enter a name and address."));
         updateInterface(NavigationMode);