This simple Java Application will convert the given decimal value to its Binary. Following code is to be executed after the user enters a value and presses 'Convert'. (Button Action) private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { int num = Integer.parseInt(jTextField1.getText()); if(num>=0){ int binary[] = new int[50]; int index = 0; do{ binary[index++]=num%2; num = num/2; } while(num>0); StringBuilder builder = new StringBuilder(); for (int i=index-1; i>=0;i--) { builder.append(binary[i]);//to concatenate the array in reverse } String text = builder.toString(); // convert to string jLabel3.setText(text); } }