Java 默认数组值

如果我们不给数组元素赋值并试图访问它们，编译器不会像简单变量的情况那样产生错误。相反，它分配的值不是垃圾值。

下面是默认的赋值

例子

// Java program to demonstrate default
// values of array elements
 
class ArrayDemo {
    public static void main(String[] args)
    {
        System.out.println("String array default values:");
        String str[] = new String[5];
        for (String s : str)
            System.out.print(s + " ");
 
        System.out.println(
            "\n\nInteger array default values:");
        int num[] = new int[5];
        for (int val : num)
            System.out.print(val + " ");
 
        System.out.println(
            "\n\nDouble array default values:");
        double dnum[] = new double[5];
        for (double val : dnum)
            System.out.print(val + " ");
 
        System.out.println(
            "\n\nBoolean array default values:");
        boolean bnum[] = new boolean[5];
        for (boolean val : bnum)
            System.out.print(val + " ");
 
        System.out.println(
            "\n\nReference Array default values:");
        ArrayDemo ademo[] = new ArrayDemo[5];
        for (ArrayDemo val : ademo)
            System.out.print(val + " ");
    }
}

输出

String array default values:
null null null null null 

Integer array default values:
0 0 0 0 0 

Double array default values:
0.0 0.0 0.0 0.0 0.0 

Boolean array default values:
false false false false false 

Reference Array default values:
null null null null null