X32专项练习部分10

• 判断推理与条件证明
• Java中的值传递
• 重写run方法
• Java枚举类
• 按位取反
• 显式调用构造函数
• Lambda表达式
• 定义二维数组
• 总目录

class Example{
    String str=new String("tarena");
    char[] ch={'a','b','c'};
    public static void main(String args[]){
        Example ex=new Example();
        ex.change(ex.str,ex.ch);
        System.out.print(ex.str+" and ");
        System.out.print(ex.ch);
    }
    public void change(String str,char ch[]){
        //引用类型变量，传递的是地址，属于引用传递
        str="test ok";
        ch[0]='g';
    }
    
    public void change(char chs[]){
        char[]chs2={'b'};
        chs=chs2;//参数副本指向新地址
    }
    public void change2(char chs[]){
        chs[0]='b';//参数副本还是指向原来地址，所以修改了值
    }
}

class Bground extends Thread{
    public static void main(String args[]){
        Bground b = new Bground();
        b.run();
    }
    public void start(){
        for(int i=0;i<10;i++){
            System.out.println("Value of i = "+i);
            // 编译通过但没输出
        }
    }
    
}

enum AccountType {
    SAVING, FIXED, CURRENT;
    private AccountType() {
        System.out.println("It is a account type");
    }
}
class EnumOne {
    public static void main(String[]args) {
        System.out.println(AccountType.FIXED);
        
    }
}

class Person1 {
    String name = "No name";
    public Person1(String nm) {
        name = nm;
    }
}
class Employee1 extends Person1 {
    String empID = "0000";
    public Employee1(String id) {
        super("nm"); // need to add
        empID = id;
    }
}
class Test {
    public static void main(String args[]) {
        Employee1 e = new Employee1("123");
        System.out.println(e.empID);
    }
}