Question

这是我的代码。它用于检查文本字符串是否是另一个文本字符串的子字符串。

public class Problem2
{
public boolean isSubstring(String T, String P)
{
    System.out.println("String T: " + T);
    System.out.println("String P: " + P);
    char[] arrayT = T.toCharArray();
    System.out.println("Array T: " + Arrays.toString(arrayT));
    System.out.println("Array T length: " + arrayT.length);
    char[] arrayP = P.toCharArray();
    System.out.println("Array P: " + Arrays.toString(arrayP));
    System.out.println("Array P length: " + arrayP.length);
    int consecutive = 0;
    boolean isTrue = false;
    for (int i = 0; i < arrayT.length; i++)
    {
        System.out.println("i: " + i);
        System.out.println("Consecutive characters before comparison: " + consecutive);
        System.out.println("Letters in T left to be compared: " + (arrayT.length - i));
        System.out.println("Unmatched letters in array P: " + (arrayP.length - consecutive));
        if(arrayT.length - i < arrayP.length - consecutive)
        {
            System.out.println("isTrue: " + isTrue);
            System.out.println("Break #1");
            break;
        }
        System.out.println("arrayT[i]: " + arrayT[i]);
        System.out.println("arrayP[consecutive]: " + arrayP[consecutive]);
        if(arrayT[i] == arrayP[consecutive])
        {
            consecutive += 1;
        }
        else
        {
            consecutive = 0;
        }
        System.out.println("Consecutive characters after comparison: " + consecutive);
        if(consecutive == arrayP.length)
        {
            System.out.println("Consecutive = Array P length, " + consecutive + " = " + arrayP.length);
            isTrue = true;
            System.out.println("isTrue: " + isTrue);
            System.out.println("Break #2");
            break;
        }
    }
    return isTrue;
}}

以下是我的测试结果。正如下面将会看到的那样，每个测试在实际断开并返回布尔值之前循环两次for循环。为什么会发生这种情况，我该如何解决？任何人的帮助将不胜感激。

Test 1
String T: MINNESOTA
String P: INNE
Array T: [M, I, N, N, E, S, O, T, A]
Array T length: 9
Array P: [I, N, N, E]
Array P length: 4
i: 0
Consecutive characters before comparison: 0
Letters in T left to be compared: 9
Unmatched letters in array P: 4
arrayT[i]: M
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 1
Consecutive characters before comparison: 0
Letters in T left to be compared: 8
Unmatched letters in array P: 4
arrayT[i]: I
arrayP[consecutive]: I
Consecutive characters after comparison: 1
i: 2
Consecutive characters before comparison: 1
Letters in T left to be compared: 7
Unmatched letters in array P: 3
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 2
i: 3
Consecutive characters before comparison: 2
Letters in T left to be compared: 6
Unmatched letters in array P: 2
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 3
i: 4
Consecutive characters before comparison: 3
Letters in T left to be compared: 5
Unmatched letters in array P: 1
arrayT[i]: E
arrayP[consecutive]: E
Consecutive characters after comparison: 4
Consecutive = Array P length, 4 = 4
isTrue: true
Break #2
    //Why does it break here, but continue to loop once again below before returning the boolean?

String T: MINNESOTA
String P: INNE
Array T: [M, I, N, N, E, S, O, T, A]
Array T length: 9
Array P: [I, N, N, E]
Array P length: 4
i: 0
Consecutive characters before comparison: 0
Letters in T left to be compared: 9
Unmatched letters in array P: 4
arrayT[i]: M
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 1
Consecutive characters before comparison: 0
Letters in T left to be compared: 8
Unmatched letters in array P: 4
arrayT[i]: I
arrayP[consecutive]: I
Consecutive characters after comparison: 1
i: 2
Consecutive characters before comparison: 1
Letters in T left to be compared: 7
Unmatched letters in array P: 3
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 2
i: 3
Consecutive characters before comparison: 2
Letters in T left to be compared: 6
Unmatched letters in array P: 2
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 3
i: 4
Consecutive characters before comparison: 3
Letters in T left to be compared: 5
Unmatched letters in array P: 1
arrayT[i]: E
arrayP[consecutive]: E
Consecutive characters after comparison: 4
Consecutive = Array P length, 4 = 4
isTrue: true
Break #2
INNE is a substring of MINNESOTA: true


Test 2
String T: MINNESOTA
String P: INEN
Array T: [M, I, N, N, E, S, O, T, A]
Array T length: 9
Array P: [I, N, E, N]
Array P length: 4
i: 0
Consecutive characters before comparison: 0
Letters in T left to be compared: 9
Unmatched letters in array P: 4
arrayT[i]: M
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 1
Consecutive characters before comparison: 0
Letters in T left to be compared: 8
Unmatched letters in array P: 4
arrayT[i]: I
arrayP[consecutive]: I
Consecutive characters after comparison: 1
i: 2
Consecutive characters before comparison: 1
Letters in T left to be compared: 7
Unmatched letters in array P: 3
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 2
i: 3
Consecutive characters before comparison: 2
Letters in T left to be compared: 6
Unmatched letters in array P: 2
arrayT[i]: N
arrayP[consecutive]: E
Consecutive characters after comparison: 0
i: 4
Consecutive characters before comparison: 0
Letters in T left to be compared: 5
Unmatched letters in array P: 4
arrayT[i]: E
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 5
Consecutive characters before comparison: 0
Letters in T left to be compared: 4
Unmatched letters in array P: 4
arrayT[i]: S
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 6
Consecutive characters before comparison: 0
Letters in T left to be compared: 3
Unmatched letters in array P: 4
isTrue: false
Break #1
    //Why does it break here, but continue to loop once again below before returning the boolean?

String T: MINNESOTA
String P: INEN
Array T: [M, I, N, N, E, S, O, T, A]
Array T length: 9
Array P: [I, N, E, N]
Array P length: 4
i: 0
Consecutive characters before comparison: 0
Letters in T left to be compared: 9
Unmatched letters in array P: 4
arrayT[i]: M
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 1
Consecutive characters before comparison: 0
Letters in T left to be compared: 8
Unmatched letters in array P: 4
arrayT[i]: I
arrayP[consecutive]: I
Consecutive characters after comparison: 1
i: 2
Consecutive characters before comparison: 1
Letters in T left to be compared: 7
Unmatched letters in array P: 3
arrayT[i]: N
arrayP[consecutive]: N
Consecutive characters after comparison: 2
i: 3
Consecutive characters before comparison: 2
Letters in T left to be compared: 6
Unmatched letters in array P: 2
arrayT[i]: N
arrayP[consecutive]: E
Consecutive characters after comparison: 0
i: 4
Consecutive characters before comparison: 0
Letters in T left to be compared: 5
Unmatched letters in array P: 4
arrayT[i]: E
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 5
Consecutive characters before comparison: 0
Letters in T left to be compared: 4
Unmatched letters in array P: 4
arrayT[i]: S
arrayP[consecutive]: I
Consecutive characters after comparison: 0
i: 6
Consecutive characters before comparison: 0
Letters in T left to be compared: 3
Unmatched letters in array P: 4
isTrue: false
Break #1
INEN is a substring of MINNESOTA: false

以下是测试用例。

public class Problem2Test
{
/**
 * Test of isSubstring method, of class Problem2.
 */
@Test
public void testIsSubstring()
{
    System.out.println("Test 1");
    String T = "MINNESOTA";
    String P = "INNE";
    Problem2 instance = new Problem2();
    boolean expResult = true;
    boolean result = instance.isSubstring(T, P);
    System.out.println(P + " is a substring of " + T + ": " + instance.isSubstring(T, P));
    assertEquals(expResult, result);

    System.out.println("Test 2");
    T = "MINNESOTA";
    P = "INEN";
    Problem2 instance2 = new Problem2();
    expResult = false;
    result = instance.isSubstring(T, P);
    System.out.println(P + " is a substring of " + T + ": " + instance.isSubstring(T, P));
    assertEquals(expResult, result);}}

Answer 1

因为您为“测试1”致电instance.isSubstring(T,P)两次 - 一次保存result变量，一次保存在System.out电话中。

Java：为什么我的for循环再循环一次然后在我第一次尝试突破之后中断？

1 个答案: