数组 Major^

publilc class Shuzu{
public static void main(String ags[]){
{
int a[]={1,2,3,4};
char b[]={a,b,c,d};
for(int i=0;i<a.length;i++){
System.out.print(a[i]);//传统方法遍历数组a
System.out.println("");
}
for(String s:b){
System.out.print("  "+s);//非传统方式遍历数组b
}
}
}

import java.util.*;
public class Shuzu1{
public static void main(String args[]){
char a[]={'a','b','c','d'};
String str=Arrays.toString(a);
System.out.println(a);
}
}

2、toString方法遍历

import java.util.*;
public class Shuzu2{
public static void main(String args[]){
int a[]={1,2,3,4},b[];
b=a;//数组属于引用类型，所以数组b与数组a的引用相同
System.out.println(a==b);//true
System.out.println(Arrays.toSting(a));
System.out.println(Arrays.toSting(b));//与上相同
}
}

import java.util.*;
public class Shuzu3{
public static void main(String args[]){
char a[]={'A','B','C','D','E','F'};
char b[]={'1','2','3','4','5','6'};
System.arraycopy(a,0,b,0,a.length);//a的数组复制到b数组
System.out.println(Arrays.toString(b));//与数组a一样
}
}

import java.util.*;
public class Shuzu5{
public static void main(String args[]){
int a[]={1,2,3,4,5},b,c;
b[]=Arrays.copyOf(a,8);//数组a只有5个元素，所以数组b的8位中后3位默认为0
System.out.println(Arrays.toString(a));//输出[1,2,3,4,5]
System.out.println(Arrays.toString(b));//输出[1,2,3,4,5,0,0,0]
c[]=Arrays.copyOfArray(a,3,5);//
System/.out.println(Arrays.toString(c))//输出[4,5]
}
}

//Arrays类的sort方法实现快速排序
//Arrays.binarySearch(数组,要查找的值)实现二分查找，返回要查找的值在数组中的索引号，若没有找到，返回0
import java.util.*;
public class Shuzu5{
public Static void mian(String args[]){
Scanner scanner=new Scanner(System.in);
int a[]={12,34,9,23,45,6,45,90,123,19,34};
Arrays.sort(a);//排序
System.out.println("输入整数，判断该整数是否在数组中:");
while(scanner.hasIntNext()){
int number=scanner.nextInt();//输入数组
int index=Arrays.binarySearch(a,number);//二分查找
if(index>0){
System.out.println(number+"和数组a中索引为"+index+"的值相同");
}
else System.out.println(number+"不与数组a的任何值相同");
System.out.println("是否继续输入整数，输入任何非整数可结束");
}
}
}

public class Shuzu6{
public static void main(String args[]){
Weekday x=Weekday.星期天;
if(x==x.Weekday.星期天){
System.out.println(x);
System.out.println("今天我休息");
}
}
}

//枚举enum
enum Weekday{
星期一,星期二,星期三,星期四,星期五,星期六,星期天
}