Import java.applet.applet; import java.awt. *; import java.awt.event. *;
Public Class Calc Extends Applet Implements ActionListener {Label Result; PANEL Knoppen; Proc PROC
Public void init () {button knop; string opschrift; proc = new proc (); result = new label ("0", label.right); knoppen = new panel (); Result.setFont (New Font ("arial" , Font.Bold, 20));
This. setLayout (New BorderLayout ()); knoppen.setLayout (New GridLayout (4, 4, 6, 6)); for (int N = 0; n <16; n ) {Opschrift = "789/456 * 123 0c = - ". Substring (n, n 1); knop = new button (Opschrift); knop.addActionListener (this); knoppen.add (knop);} this.add (Result, borderLayout.North); this. Add (Knoppen, BorderLayout.center);
Public void actionperformed (ActionEvent E) {Button B; Char C; B = (Button) (E.GETSOURCE ()); c = B.Getlabel (). Charat (0);
IF (c == 'c') proc.schoon (); else if (c == '=') proc.reken (); else if (c> = '0' && c <= '9') proc.cijfer (c-'0 '); Else Proc.Operatie (C); Result.Settext (" proc.scherm);}} / **** / class proc {long war wars, vorige, scherm; char Operator
PROC () {Schoon ();
Void Schoon () {waarde = 0; vorige = 0; operator = ' '; scherm = 0;}
Void Reken () {Switch (Operator) {Case ' ': Vorige = Waarde; Break; Case '-': Vorige - = Waarde; Break; Case '*': vorige * = Waarde; Break; Case '/' : vorige / = Waarde; Break;} scherm = vorige; waarde = 0;} void cijfer (int N) {waarde = 10 * waarde n; scherm = Waarde;}
Void Operatie (Char C) {reken (); operator = C;}}
Two classes, realizing simple calculators, worth learning, go on Google search, still very good, I must not write now!
