| package com.siyeh.igtest.performance.manual_array_to_collection_copy; |
| |
| import java.util.List; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Random; |
| |
| public class ManualArrayToCollectionCopy { |
| |
| void foo(Object[] xs, Object[] ys) { |
| List list = new ArrayList(); |
| for (int i = 0; (i < (int)(xs.length)); i++) { |
| list.add(xs[i]); |
| } |
| list.addAll(Arrays.asList(xs).subList(0, xs.length)); |
| } |
| |
| List arg(Object[] os) { |
| List list = new ArrayList(); |
| for (int i = 0; i < os.length - 1; i++) { |
| list.add(os[i + 1]); |
| } |
| Object[] ps = new Object[os.length - 1]; |
| for (int i = 1; i < os.length - 1; i++) { |
| ps[i - 1] = os[i]; |
| } |
| return list; |
| } |
| |
| ArrayList<Integer> boom(int[] ints) { |
| final ArrayList<Integer> list = new ArrayList<Integer>(ints.length); |
| for (int i = 0; i < ints.length; ++i) { |
| // no inspection/ quick fix here because it is an array of primitives |
| list.add(ints[i]); |
| } |
| return list; |
| } |
| |
| List<String> shouldWorkForForeachToo(String[] strings) { |
| List<String> list = new ArrayList(); |
| for (String string : strings) { |
| list.add(string); |
| } |
| return list; |
| } |
| |
| void replaceWithSubList(List<String> parameters, String[] args) { |
| for (int i = 2; i < args.length; ++i) |
| { |
| parameters.add(args[i]); |
| } |
| } |
| |
| private static Random random = new Random(); |
| private static final int N = 10; |
| public static int nextInt() { |
| return random.nextInt(N); |
| } |
| |
| public static void main(String[] args) { |
| List<Integer>[] li = new List[N]; |
| for (int i = 0; i < N; ++i) { |
| li[i] = new ArrayList<Integer>(); |
| } |
| Integer[] values = new Integer[N]; |
| for (int i = 0; i < N; ++i) { |
| values[i] = i; |
| } |
| //This loop is highlighted. |
| for (int i = 1; i < N; ++i) { |
| li[nextInt()].add(values[i]); |
| } |
| } |
| } |