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Java 展平整型数组的列表_Java_Arrays_Collections - Fatal编程技术网

Java 展平整型数组的列表

Java 展平整型数组的列表,java,arrays,collections,Java,Arrays,Collections,我有一个Java 7中的int数组列表。 最后,我需要将整个列表展平为一个串联的int数组 List<int[]> list=new ArrayList<int[]>(); list.add(new int[]{0,1}); list.add(new int[]{2,3}); System.out.println(list.flatten()); Output expected - int[]{0,1,2,3} List List=new ArrayList();

我有一个Java 7中的int数组列表。
最后,我需要将整个列表展平为一个串联的int数组

List<int[]> list=new ArrayList<int[]>();
list.add(new int[]{0,1});
list.add(new int[]{2,3});
System.out.println(list.flatten());

Output expected - 
int[]{0,1,2,3}
List List=new ArrayList();
添加(新的int[]{0,1});
添加(新的int[]{2,3});
System.out.println(list.flatte());
预期产出-
int[]{0,1,2,3}
实现这一点最优雅的方法是什么?

您可以使用流:

删除-Java 7后来被偷偷带进来

我不认为你能使它比:

int newlen = 0;
for( int[] a: list ){
    newlen += a.length;
}
int[] out = new int[newlen];
int pos = 0;
for( int[] a: list ){
    System.arraycopy( a, 0, out, pos, a.length );
    pos += a.length;
}

这在Java7中不是一个选项