数组索引 HighArray 和 HighArrayApp？

Question

public int find(long searchKey) 
{

    int j;
    for(j=0; j<nElems; j++) {  // for each element,
        if(a[j] == searchKey)     // found search value?
            return j;                // then exit loop before end (exits entire function)
    }
    // reached end of for loop
    return nElems;             // thus, can't find it
} // end find()
public void insert(long value) 
{
    a[nElems] = value;
    nElems++; 
}

我正在尝试将此功能实现到 return 搜索键的索引，而不是搜索键的值。这是主要的 class，我无法显示索引

int searchKey = 33; // search for item
    int indexToDisplay = j
    if( arr.find(searchKey) )
        System.out.println("Found " + searchKey + " at index: " + j );
    else
        System.out.println("-1");

Answer 1

int searchKey = 33; // search for item
int indexToDisplay = j
if( arr.find(searchKey) )
    System.out.println("Found " + searchKey + " at index: " + j );
else
    System.out.println("-1");

您实际上将 indexToDisplay 设置为空，您要做的是将其设置为 find() 方法的 return 值，就像这样：

int indexToDisplay = arr.find(searchKey);

然后，由于您的查找方法不是 return 布尔值，您可以检查它是否是数组中的有效索引，如下所示：

if(indexToDisplay != -1)
    System.out.println("Found " + searchKey + " at index: " + j );

我不太确定 nElems 是什么，但是如果您在数组中找不到您要查找的内容，我会推荐 returning -1。所以我们总共有这样的东西：

public int find(long searchKey) 
{
    int j;
    for(j=0; j<nElems; j++) {  // for each element,
        if(a[j] == searchKey)     // found search value?
            return j;                // then exit loop before end (exits entire function)
    }
    // reached end of for loop
    return -1;             // thus, can't find it
} // end find()
public void insert(long value) 
{
    a[nElems] = value;
    nElems++; 
}

我们这样称呼它：

int searchKey = 33; // search for item
int indexToDisplay = arr.find(searchKey);
if(indexToDisplay != -1)
    System.out.println("Found " + searchKey + " at index: " + indexToDisplay );
else
    System.out.println("-1");

数组索引 HighArray 和 HighArrayApp？

Array Indexing HighArray and HighArrayApp?

java

arrays

indexing