Android Development Android UI and Layouts 3

Question 1

What is the role of the merge tag in Android XML layouts?

Accepted Answer

To eliminate redundant view groups when including layouts

Answer

The tag helps reduce the depth of the view hierarchy by eliminating a redundant parent layout when using .

Question 2

Which ConstraintLayout feature allows multiple views to be evenly spaced using a chain?

Accepted Answer

Chain style

Answer

Chains in ConstraintLayout allow you to control how a group of views distribute space and position relative to each other.

Question 3

What is a ViewHolder pattern used for in Android?

Accepted Answer

To cache view references and avoid repeated calls to findViewById

Answer

The ViewHolder pattern stores references to views within a list item, eliminating the costly lookup via findViewById on every scroll.

Question 4

Which XML attribute sets a fixed aspect ratio for a view in ConstraintLayout?

Accepted Answer

app:layout_constraintDimensionRatio

Answer

app:layout_constraintDimensionRatio constrains one dimension of a view relative to the other based on a specified ratio.

Question 5

What method inflates a layout resource in Android?

Accepted Answer

Both A and B

Answer

Both LayoutInflater.inflate() and View.inflate() can be used to instantiate a layout XML file into its corresponding View objects.

Android Development Practice Test