private Button sButton;    private TextView mTextView;    private Button fButton;    private int[] sArray={13,25,38,34,42};    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_ex0313);                mTextView=(TextView)findViewById(id.Ex0313DisplayText);        sButton=(Button)findViewById(id.Ex0313SizeButton);        sButton.setOnClickListener(new Button.OnClickListener() {                        @Override            public void onClick(View v) {                // TODO Auto-generated method stub                                Random mRandom=new Random();                int mNum = mRandom.nextInt(4);                mTextView.setTextSize(sArray[mNum]);            }        });                        fButton=(Button)findViewById(id.Ex0313FontsButton);        fButton.setOnClickListener(new Button.OnClickListener() {                        @Override            public void onClick(View v) {                // TODO Auto-generated method stub                Typeface fTypeface=Typeface.createFromAsset(getResources().getAssets(),"fonts/PentaGram‘sMalefissent.ttf");                mTextView.setTypeface(fTypeface);            }        });                    }

     <TextView        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:id="@+id/Ex0313DisplayText"     android:layout_marginLeft="20dp"        android:layout_marginTop="10dp"                android:text="@string/hello_world" /><Button android:id="@+id/Ex0313SizeButton"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginLeft="20dp"        android:layout_marginTop="50dp"        android:text="@string/ex0313sizebutton" /><Button android:id="@+id/Ex0313FontsButton"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:layout_marginLeft="20dp"        android:layout_marginTop="100dp"        android:text="@string/ex0313fontsbutton" />