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  • java各种数据类型的数组元素的默认值

    public class DataTypeDefaultValue {
        public static void main(String[] args) {
            // string类型数组的默认值null
            // 对于引用类型的属性的默认值是null,如String类型
            System.out.println("查看String类型中数组的默认值:");
            String[] str = new String[4];
            str[0] = "aa";
            str[1] = "bb";
            str[2] = "cc";
            for (int i = 0; i < 4; i++) {
                System.out.println(str[i]);
            }
            // 对于short,int,long,byte而言,创建数组的默认值是0
            System.out.println("查看int类型数组的默认值:");
            int[] score = new int[4];
            score[0] = 90;
            score[1] = 89;
            score[2] = 34;
            for (int i = 0; i < score.length; i++) {
                System.out.println(score[i]);
            }
            System.out.println("查看short类型数组的默认值:");
            short[] score1 = new short[4];
            score1[0] = 90;
            for (int i = 0; i < score1.length; i++) {
                System.out.println(score1[i]);
            }
            System.out.println("查看long类型数组的默认值:");
            long[] score2 = new long[4];
            score2[0] = 90;
            for (int i = 0; i < score2.length; i++) {
                System.out.println(score2[i]);
            }
            System.out.println("查看byte类型数组的默认值:");
            byte[] score3 = new byte[4];
            score3[0] = 90;
            for (int i = 0; i < score3.length; i++) {
                System.out.println(score3[i]);
            }
            // 对于float double而言,默认值是0.0
            System.out.println("查看float类型数组的默认值:");
            float[] score4 = new float[4];
            score4[0] = 23;
            for (int i = 0; i < score4.length; i++) {
                System.out.println(score4[i]);
            }
            System.out.println("查看double类型数组的默认值:");
            double[] score5 = new double[4];
            score5[0] = 45;
            for (int i = 0; i < score5.length; i++) {
                System.out.println(score5[i]);
            }
            // 对于char类型
            // char类型数组的默认值是空格
            System.out.println("查看char类型数组的默认值:");
            char[] ch = new char[4];
            ch[0] = 'p';
            for (int i = 0; i < ch.length; i++) {
                System.out.println(ch[i]);
            }
            // 对于boolean类型的数组默认值
            // boolean类型数组的默认值是false
            System.out.println("查看boolean数组的默认值:");
            boolean[] b = new boolean[4];
            b[0] = true;
            for (int i = 0; i < b.length; i++) {
                System.out.println(b[i]);
            }
            /// 引用类型数组的默认值是null
            class Person {
            }
            System.out.println("查看引用类型的数组默认值:");
            Person[] p = new Person[4];
            for (int i = 0; i < p.length; i++) {
                System.out.println(p[i]);
            }
        }
    }

    运行结果:

    查看String类型中数组的默认值:
    aa
    bb
    cc
    null
    查看int类型数组的默认值:
    90
    89
    34
    0
    查看short类型数组的默认值:
    90
    0
    0
    0
    查看long类型数组的默认值:
    90
    0
    0
    0
    查看byte类型数组的默认值:
    90
    0
    0
    0
    查看float类型数组的默认值:
    23.0
    0.0
    0.0
    0.0
    查看double类型数组的默认值:
    45.0
    0.0
    0.0
    0.0
    查看char类型数组的默认值:
    p
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  • 原文地址:https://www.cnblogs.com/zhangwuji/p/9719420.html
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