arrays - java parentheses around class while storing reference to button -

arrays - java parentheses around class while storing reference to button -

i in aprocess of learnning java.

i have code java reference:-

public class buttonlist extends applet implements actionlistener { string msg = ""; button blist[] = new button[3]; public void init() { button yes = new button("yes"); button no = new button("no"); button maybe = new button("undecided"); // store references buttons added blist[0] = (button) add(yes); <<<<<<<<<<<<<<<<<<<<<<<<<<<<< here blist[1] = (button) add(no); blist[2] = (button) add(maybe); // register receive action events for(int = 0; < 3; i++) { blist[i].addactionlistener(this); } }

and wonder "(button) add(yes) " stands .

why should blist[] re assigned button if declared button on previous paragraph.

also button whithin parentheses stands here ?

(button) myvar inserts runtime check myvar assigned button compiler can safely assume myvaris button. if myvar not button @ runtime, exception thrown.

refer explicit casting more information

java arrays button control