What is android:layout_alignLeft in Android?

Question

i couldnt understand the attribute android:layout_alignLeft .i am new to android development.

<RelativeLayout 
        android:id="@+id/r5"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/r4"

        > <TextView
              android:id="@+id/tv3"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_centerHorizontal="true"
              android:layout_centerVertical="true"
              android:layout_marginTop="10dp"
               android:textSize="16sp"
              android:textColor="#663300"
              android:text="TextView"

               />

          <TextView
              android:id="@+id/tv5"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"            
              android:layout_marginTop="10dp"

              android:layout_alignLeft="@id/tv3"
               android:textSize="16sp"
              android:textColor="#663300"
              android:text="TextView"


               />
         <TextView
              android:id="@+id/tv6"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_toRightOf="@id/tv5"
              android:layout_marginTop="10dp"
               android:textSize="16sp"
              android:textColor="#663300"
              android:text="TextView"

               />

          </RelativeLayout>

anyone can explain clearly?what is the difference between android:layout_Leftof and android:layout_alignLeft?

Answer 1

layout_alignLeft makes the left edge of your view match the left edge of the view whose ID you use as the parameters.

layout_toLeftOf makes your view placed to the left side of the view whose ID you use (the right edge will be aligned with the left edge of the other view).