java arraycopy()

System.arraycopy()

System.arraycopy(digest, index1, frame, index2, digest.length);
// 把digest中的内容从第index1个开始复制到frame中去，从frame的第index2开始，总共要复制的长度为 digest.length

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);
        }
    }
}
运行结果：
A
B
C
D
E

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