1、編寫一個ATM機類，有屬性：所屬銀行、顯示余額、，有方法：取款、存款、查詢余額

/*
* 取款機實體類
* ATM
*/
public class ATM {
String affiliatedBank;// 聲明所屬銀行
String keyboard; // 鍵盤
Double displayBalance; // 顯示余額
String horn; // 喇叭
// 無參構造函數

public ATM() {

}

/*
* 封裝屬性，getXXX（）取值,setXXXX()賦值
*/
public String getAffiliatedBank() {
return affiliatedBank;
}

public void setAffiliatedBank(String affiliatedBank) {
this.affiliatedBank = affiliatedBank;
}

public String getKeyboard() {
return keyboard;
}

public void setKeyboard(String keyboard) {
this.keyboard = keyboard;
}

public Double getDisplayBalance() {
return displayBalance;
}

public void setDisplayBalance(Double displayBalance) {
this.displayBalance = displayBalance;
}

public String getHorn() {
return horn;
}

public void setHorn(String horn) {
this.horn = horn;
}

// ATM取款方法
public void withdrawals(Double sum) {
Double withdrawalBalance; // 賬戶余額
System.out.println("歡迎使用" + affiliatedBank + "ATM01");
withdrawalBalance = displayBalance - sum;
System.out.println("ATM賬戶余額" + withdrawalBalance + "ATM011");

}

// ATM存款方法
public void deposits(Double sum1) {
Double withdrawalBalance; // 賬戶余額
System.out.println("歡迎使用" + affiliatedBank + "ATM02");
withdrawalBalance = displayBalance + sum1;
System.out.println("ATM賬戶余額" + withdrawalBalance + "ATM012");
}

// 查詢存款後ATN余額方法
public void inquiries3(Double sum1) {
Double c = displayBalance + sum1; // ATM機余額
displayBalance = c;
System.out.println("歡迎使用" + affiliatedBank + "ATM03");
System.out.println("ATM賬戶余額" + displayBalance + sum1 + "ATM013");
}

// 取款後查詢ATM余額方法
public void inquiries(Double sum1) {
Double c = displayBalance - sum1;
displayBalance = c;
System.out.println("歡迎使用" + affiliatedBank + "ATM03");
System.out.println("ATM賬戶余額" + displayBalance + "ATM013");
}

// 查詢ATM余額方法
public void inquiries() {
System.out.println("歡迎使用" + affiliatedBank + "ATM03");
System.out.println("ATM賬戶余額" + displayBalance + "ATM013");
}
}

/*
* 儲戶實體類
*
*/
public class Depositor {
String accountNumber;// 賬號
String affiliatedBank;// 所屬銀行
Double depositAmount;// 賬戶余額
ATM atm; // ATM 對象
Bank bank;// Bank 對象

public String getAccountNumber() {
return accountNumber;
}

public void setAccountNumber(String accountNumber) {
this.accountNumber = accountNumber;
}

public String getAffiliatedBank() {
return affiliatedBank;
}

public void setAffiliatedBank(String affiliatedBank) {
this.affiliatedBank = affiliatedBank;
}

public Double getDepositAmount() {
return depositAmount;
}

public void setDepositAmount(Double depositAmount) {
this.depositAmount = depositAmount;

}
// 儲戶取款方法
public void withdrawals2(Double sum) {
Double withdrawalBalance; //賬戶余額
System.out.println("歡迎使用"+affiliatedBank+"ATM0");
withdrawalBalance=depositAmount-sum;
System.out.println("儲戶賬戶余額"+withdrawalBalance+"ATM01");
}

// 儲戶取存款方法
public void deposits2(Double sum1) {
Double withdrawalBalance; //賬戶余額
System.out.println("歡迎使用"+affiliatedBank+"ATM02");
withdrawalBalance=depositAmount+sum1;
System.out.println("儲戶賬戶余額"+withdrawalBalance+"ATM12");
}

// 取款查詢余額方法
public void inquiries22(Double sum) {
double b=depositAmount-sum;
depositAmount=b;
System.out.println("歡迎使用"+affiliatedBank+"ATM031");
System.out.println("儲戶賬戶余額"+depositAmount+"ATM0131");
}
// 儲戶存款增加查詢余額方法
public void inquiries2(Double sum) {
//atm 余額增加
//atm.inquiries3(sum);

double b=depositAmount+sum;
depositAmount=b;
System.out.println("歡迎使用"+affiliatedBank+"ATM031");
System.out.println("儲戶賬戶余額"+depositAmount+"ATM0131");
}
// 查詢余額方法
public void inquiries2() {
System.out.println("歡迎使用"+affiliatedBank+"ATM03");
System.out.println("儲戶賬戶余額"+depositAmount+"ATM013");

}
}

/*
* 銀行實體類
*
*/
public class Bank {
String bankName;// 銀行名稱
String address;// 地址
Double depositAmount;// 存款金額

public String getBankName() {
return bankName;
}

public void setBankName(String bankName) {
this.bankName = bankName;
}

public String getAddress() {
return address;
}

public void setAddress(String address) {
this.address = address;
}

public Double getDepositAmount() {
return depositAmount;
}

public void setDepositAmount(Double depositAmount) {
this.depositAmount = depositAmount;
}

// 銀行取款方法
public void withdrawals1(Double sum) {
Double withdrawalBalance; // 賬戶余額
System.out.println("歡迎使用" + bankName + "櫃臺0");
withdrawalBalance = depositAmount - sum;
System.out.println("銀行賬戶余額" + withdrawalBalance + "櫃臺00");

}

// 銀行存款方法
public void deposits1(Double sum1) {
Double withdrawalBalance; // 賬戶余額
System.out.println("歡迎使用" + bankName + "櫃臺1");
withdrawalBalance = depositAmount + sum1;
System.out.println("銀行賬戶余額" + withdrawalBalance + "櫃臺11");
}
// 查詢銀行余額方法
public void inquiries11(Double sum) {
Double a=depositAmount+sum;
depositAmount=a;
System.out.println("歡迎使用" + bankName + "櫃臺2");
System.out.println("銀行賬戶余額" + depositAmount + "櫃臺22");
}
// 查詢銀行余額方法
public void inquiries1(Double sum) {
Double a=depositAmount-sum;
depositAmount=a;
System.out.println("歡迎使用" + bankName + "櫃臺2");
System.out.println("銀行賬戶余額" + depositAmount + "櫃臺22");
}
// 查詢銀行余額方法不帶參
public void inquiries1() {
System.out.println("歡迎使用" + bankName + "櫃臺21");
System.out.println("銀行賬戶余額" + depositAmount + "櫃臺221");
}
}

類和對象，類定義了對象的特征和行為。屬性，方法。