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.base; 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]