数组扩容、数组填充、数组合并

数组扩容

public class Main {
    public static void main(String[] args) {
        String[] names = new String[] { "A", "B", "C" };
        String[] extended = new String[5];
        extended[3] = "D";
        extended[4] = "E";
        System.arraycopy(names, 0, extended, 0, names.length);
        for (String str : extended){
            System.out.println(str);
        }
    }
}

A
B
C
D
E

数组填充

public class FillTest {
    public static void main(String args[]) {
        int array[] = new int[6];
        Arrays.fill(array, 100);
        for (int i=0, n=array.length; i < n; i++) {
            System.out.println(array[i]);
        }
        System.out.println();
        Arrays.fill(array, 3, 6, 50);
        for (int i=0, n=array.length; i< n; i++) {
            System.out.println(array[i]);
        }
    }
}

100
100
100
100
100
100

100
100
100
50
50
50

数组合并

public class Main {
    public static void main(String args[]) {
        String a[] = { "A", "E", "I" };
        String b[] = { "O", "U" };
        List list = new ArrayList(Arrays.asList(a));
        list.addAll(Arrays.asList(b));
        Object[] c = list.toArray();
        System.out.println(Arrays.toString(c));
    }
}

[A, E, I, O, U]

来源：CSDN

作者：Dr_W

链接：https://blog.csdn.net/qq_42363032/article/details/103659683