JAVA : JOPTIONPANE JOptionPane.showMessageDialog: Permit to create a windows where you can write message which will be visible on screen. a JOptionPane.showInputDialog: Permit to create a windows where you can insert an element, for example , numbers end characters. JOPTIONPANE.SHOWMESSAGEDIALOG Str= "esempio di prova! " JOptionPane.showMessageDialog(null,str) JOPTIONPANE.SHOWINPUTDIALOG String stin=JOptionPane.showInputDialog("inserire un numero"); int numero=Integer.parseInt(stin); JAVA: CYCLE FOR AND WHILE While(condition){ Body of cycle;} Condition: is the condition of the loop control , when the condition is true the loop body is executed. For(variable declaration; condition; incrementing variable){ Body of cycle;} Variable: is the control variable of the loop Condition: is equal to the while loop Incrementing: is the incrementing of variable until the condition is false. This permit to stop the cycle.