java - 我需要帮助重命名数组中的元素

Question

我在学校做一个java项目，我们遇到了以下问题:

rename – changes the name of an existing sheet

public int rename(String currentName, String newName)

rename is passed two sheet names. Renaming should only be performed if the currentName sheet name is in the list and the newName sheet name isn’t. Otherwise rename does nothing (i.e. the list is unaffected). If the currentName is successfully changed to the newName then the method returns the index position of the sheet renamed. Otherwise it returns -1.

这就是我目前所拥有的

public int rename(String currentName, String newName) {
    int i = 0;
    for (i=0; i<SheetsNames.length; i++) {
        if (SheetsNames[i].equals(currentName)) {
            SheetsNames[i] = newName;
                return i;
        }
    }
    return -1;
}

我得到了重命名部分，但我无法让它不重命名为同名的东西

Answer 1

这是解决方案。

1) 输入参数经过验证

2) 在数组中查找字符串并返回索引

public class SheetNames {

    public Integer changeSheetName(String[] sheetNames, String currentName, String newName) {

        if (sheetNames == null || sheetNames.length == 0 || currentName == null || newName == null) {
            throw new IllegalArgumentException("Invalid input");
        }

        Integer replacedIndex = Arrays.asList(sheetNames).indexOf(currentName);
        if (replacedIndex != -1) {
            sheetNames[replacedIndex] = newName;
        }
        System.out.println(Arrays.toString(sheetNames));
        return replacedIndex;
    }
}

Junit 测试:-

public class SheetNamesTest {

    private SheetNames sheetNames;

    @Before
    public void setup() {
        sheetNames = new SheetNames();
    }

    @Test
    public void shouldReplaceSheetName() {
        String[] sheetNamesArr = {"dennis", "john", "dan"};
        Assert.assertEquals(new Integer(1), sheetNames.changeSheetName(sheetNamesArr, "john", "peter"));

        String[] sheetNamesArr2 = {"john", "dan"};
        Assert.assertEquals(new Integer(0), sheetNames.changeSheetName(sheetNamesArr2, "john", "peter"));
    }

    @Test
    public void shouldNotReplaceSheetName() {
        String[] sheetNamesArr = {"dennis", "johnhunt", "dan"};
        Assert.assertEquals(new Integer(-1), sheetNames.changeSheetName(sheetNamesArr, "john", "peter"));
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionWhenSheetNameIsNull() {
        sheetNames.changeSheetName(null, "john", "peter");
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionWhenSheetNameIsEmpty() {
        String[] sheetNamesArr = {};
        sheetNames.changeSheetName(sheetNamesArr, "john", "peter");
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionWhenCurrentNameIsNull() {
        String[] sheetNamesArr = {"dennis", "johnhunt", "dan"};
        sheetNames.changeSheetName(sheetNamesArr, null, "peter");
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionWhenNewNameIsNull() {
        String[] sheetNamesArr = {"dennis", "johnhunt", "dan"};
        sheetNames.changeSheetName(sheetNamesArr, "john", null);
    }

}