java - JUnit 测试用例失败。 java.lang.AssertionError : expected:<[I@12c5431> but was:<[I@14b6bed> 错误

Question

我已经面对这个问题一段时间了，它开始让我感到沮丧。代码需要返回最接近 val 的 k 个元素。如果 k 为负，此方法将抛出 IllegalArgumentException 并在 k == 0 或 k > a.length 时返回零长度数组。当我针对此方法运行测试用例时，它报告:

There was 1 failure:
1) nearestKTest(SelectorTest)
java.lang.AssertionError: expected:<[I@12c5431> but was:<[I@14b6bed>
       at SelectorTest.nearestKTest(SelectorTest.java:21)

FAILURES!!!
Tests run: 1,  Failures: 1

我知道这意味着预期与实际不符。我就是想不通。 :(

public static int[] nearestK(int[] a, int val, int k) {
  int[] b = new int[10];
  for (int i = 0; i < b.length; i++){
     b[i] = Math.abs(a[i] - val);
  }
  Arrays.sort(b);      
  int[] c = new int [k];
  for (int i = 0; i < k; i++){
     if (k < 0){
        throw new IllegalArgumentException("k is not invalid!");
     }
     else if (k == 0 || k > a.length){
     return new int[0];}
     else{
     c[i] = b[i];}   
  }
  return c;   
}


Test case:

import org.junit.Assert;
import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;


public class SelectorTest {


   /** Fixture initialization (common initialization
    *  for all tests). **/
   @Before public void setUp() {
   }


   /** A test that always fails. **/
   @Test public void nearestKTest() {
    int[] a = {2, 4, 6, 7, 8, 10, 13, 14, 15, 32};
    int[] expected = {6, 7};
    int[] actual = Selector.nearestK(a, 6, 2);
    Assert.assertEquals(expected,actual);
   }
}

Answer 1

您正在比较 Object 引用。要么使用 Arrays.equals比较数组内容

Assert.assertTrue(Arrays.equals(expected, actual));

或 JUnit assertArrayEquals

Assert.assertArrayEquals(expected, actual);

正如@Stewart 所建议的。显然后者更简单。