Java学习笔记day4–Arrays工具类的基本使用

package day4_array;
import java.util.Arrays;
public class ArrayBool {
    public static void main(String[] args) {
        //java.util.Arrays工具类.操作数组的工具类，包含了很多操作数组的方法
        
        //1.boolean equals();
        int arr1[]=new int[] {1,2,3,4};
        int[] arr2=new int[] {1,3,2,4};
        System.out.println(Arrays.equals(arr1,arr2));
        
        //2.toString遍历输出数组
        System.out.println(Arrays.toString(arr1));
        
        //3.fill,将指定的值填到数组中，实现替换
        Arrays.fill(arr1,10);//将arr1中元素全部换成10
        System.out.println(Arrays.toString(arr1));
        
        //4.sort,排序
        arr1=new int[] {23,44,5,1};
        Arrays.sort(arr1);
        System.out.println(Arrays.toString(arr1));
        
        //5.int binarySearch(int[] a,int key)二分法查找
        int[] number=new int[] {2,5,7,8,10,15,18,20,22,25,28};
        int index=Arrays.binarySearch(number, 19);
        if(index>=0) {
            System.out.println("找到了");
        }else
            System.out.println("没找到");
        
    }
}