Java创建数组的三种形式

Java创建数组的三种形式

测试类：

package cn.wsyjlly. ;import java.util.Arrays;/** * @author wsyjlly * @create 2019.08.18 - 15:11 **/public class StringOperator {    public static void main(String[] args) {        //方式一：声明并赋初值，声明和赋值不可以分开写        String[] str1 = {"aaa","bbb","ccc"};        //方式二：先声明，后赋值，声明和赋值可以分开写。        String[] str2 = new String[]{"aaa","bbb","ccc"};        //方式三：先声明，后赋默认值，声明和赋值可以分开写。        String[] str3;        str3 = new String[3];        Character[] str4 = new Character[3];        Integer[] str5 = new Integer[3];        char[] str6 = new char[3];        byte[] str7 = new byte[3];        short[] str8 = new short[3];        int[] str9 = new int[3];        long[] str10 = new long[3];        float[] str11 = new float[3];        double[] str12 = new double[3];        boolean[] str13 = new boolean[3];        System.out.println(Arrays.toString(str1));        System.out.println(Arrays.toString(str2));        System.out.println(Arrays.toString(str3));        System.out.println(Arrays.toString(str4));        System.out.println(Arrays.toString(str5));        System.out.println("char"+Arrays.toString(str6));        System.out.println("byte"+Arrays.toString(str7));        System.out.println("short"+Arrays.toString(str8));        System.out.println("int"+Arrays.toString(str9));        System.out.println("long"+Arrays.toString(str10));        System.out.println("float"+Arrays.toString(str11));        System.out.println("double"+Arrays.toString(str12));        System.out.println("boolean"+Arrays.toString(str13));    }}

测试结果：

[aaa, bbb, ccc][aaa, bbb, ccc][null, null, null][null, null, null][null, null, null]char[ ,  ,  ]byte[0, 0, 0]short[0, 0, 0]int[0, 0, 0]long[0, 0, 0]float[0.0, 0.0, 0.0]double[0.0, 0.0, 0.0]boolean[false, false, false]