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Steven Sierra Forero
3,486 PointsWhat is the difference between @+id and @id?
The code challenge rejected to use @+id/captionField and instead suggested to use @id/captionField, what is the difference?
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<EditText
android:id="@+id/captionField"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_alignParentTop="true"
android:hint="Enter a caption" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@id/captionField"
android:src="@drawable/grumpy_cat" />
</RelativeLayout>
1 Answer
Greg Schmidt
5,908 PointsWhen you use the +sign you are instructing the parser(or builder) to create a new entry in R.java. Without the + you are referring to an id that has already been created, so the parser links it to the id which has already been created.