Arrarys 详解

package collectionApi;

import java.util.Arrays;
import java.util.List;

public class ArrarysApi {

	public static void main(String[] args) {
		List<String> list = Arrays.asList("ssdf", "sadf", "adsfa");
		// Arrays.asList(T... a) 数组转成List
		System.out.println(String.join("-", list)); // list 转成 String : ssdf-sadf-adsfa
		
		String[] strings = {"asf", "sdf", "ewr"};
		String string = Arrays.toString(strings); // p1 boolean[], byte[], char[], double[]
		System.out.println(string); // [asf, sdf, ewr]
		
		int[] nArr = {3, 5, 1, 3, 2, 9, 56, 2};
		Arrays.sort(nArr); // 升序排序
		System.out.println(Arrays.toString(nArr));
		int[] nArr1 = {3, 5, 1, 3, 2, 1, 0, 2};
		Arrays.sort(nArr1, 2, 6);  // 排序范围为index = 2 → 6 不包含6
		System.out.println(Arrays.toString(nArr1)); // [3, 5, 1, 1, 2, 3, 0, 2]
		
		Arrays.fill(nArr1, 2, 6, -1); // index = 2 → 6 填充-1
		System.out.println(Arrays.toString(nArr1)); //[3, 5, -1, -1, -1, -1, 0, 2]
		Arrays.fill(nArr, -2); // 填充-2
		
		int[] n2 = Arrays.copyOf(nArr, 3); //赋值数组
		System.out.println(Arrays.toString(n2));  // [-2, -2, -2]
		int[] n3 = Arrays.copyOfRange(nArr, 1, 4); // 直接范围复制数组(Index = 1→4): 123
		System.out.println(Arrays.toString(n2));  // [-2, -2, -2]
		
	}

}