hardcoded string “row three”, should use @string resource

It is not good practice to hard code strings into your layout files. You should add them to a string resource file and then reference them from your layout.

This allows you to update every occurrence of the word “Yellow” in all layouts at the same time by just editing your strings.xml file.

It is also extremely useful for supporting multiple languages as a separate strings.xml file can be used for each supported language.

example: XML file saved at res/values/strings.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="yellow">Yellow</string>
</resources>

This layout XML applies a string to a View:

<TextView android:layout_width="fill_parent"
          android:layout_height="wrap_content"
          android:text="@string/yellow" />

Similarly colors should be stored in colors.xml and then referenced by using @color/color_name

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="Black">#000000</color>
</resources>