如何只顯示我的3個陣列的邏輯大小？

我有 3 個陣列，oddList、negativeList 和 evenList，它們從 masterArray 中獲取數字并相應地對它們進行排序。當我列印 3 個陣列時，如果陣列中的某些索引未填充，它會自動填充 0.0 我需要弄清楚如何擺脫這些零并僅使用陣列的邏輯大小。

public static void negoddeven(double masterArray[]){
    int z;
    int size = 0;
    int sum = 0;
    double[] negativeList = new double[10], oddList = new double[10], evenList = new double[10];

    for(z = 0; z < masterArray.length; z  ){
        for(int i = 0; i < size; i  ){
        if(masterArray[z]%2 != 0){
            sum = oddList[z];
            if(size < oddList.length){
            oddList[z] = masterArray[z];
            size  ;
        }}
        else if(masterArray[z] < 0){
            if(size < negativeList.length){
            negativeList[size] = masterArray[z];
            size  ;
        }}
        else if(masterArray[z]%2 == 0){
            if(size < negativeList.length){
            evenList[size] = masterArray[z];
            size  ;
        }}
        }
    }
    System.out.print("\nThe numbers in the odd list are: "   Arrays.toString(oddList));
    System.out.print("\nThe numbers in the negative list are: "   Arrays.toString(negativeList));
    System.out.print("\nThe numbers in the even list are: "   Arrays.toString(evenList)   "\n");
    }

uj5u.com熱心網友回復：

使用動態List而不是固定大小的陣列來收集masterArray.

此外，負值應與奇偶校驗分開計算。

public static void negOddEven(double ... masterArray) {
    int sum = 0;
    List<Double> 
        negativeList = new ArrayList<>(), 
        oddList = new ArrayList<>(), 
        evenList = new ArrayList<>();

    for (int i = 0; i < masterArray.length; i  ) {
        double z = masterArray[i];
        
        if (z < 0) {
            negativeList.add(z);
        }
        if (z % 2 == 0) {
            evenList.add(z);
        } else {
            oddList.add(z);
            sum  = z;
        }
    }
    System.out.println("The numbers in the odd list are: "   oddList   "; sum = "   sum);
    System.out.println("The numbers in the negative list are: "   negativeList);
    System.out.println("The numbers in the even list are: "   evenList   "\n");
}

測驗：

negOddEven(1, 2, 3, 0, 4.5, -2, -0.0, -12.2);

輸出：

The numbers in the odd list are: [1.0, 3.0, 4.5, -12.2]; sum = -4
The numbers in the negative list are: [-2.0, -12.2]
The numbers in the even list are: [2.0, 0.0, -2.0, -0.0]

如果由于某些限制而不允許使用串列，而只能使用陣列，則需要為所有陣列的實際長度引入單獨的計數器。使用以下方法切斷陣列中未使用的單元格也很有意義Arrays.copyOf：

public static void negOddEven(double ... masterArray) {
    int sum = 0;
    double[] 
        negList  = new double[10], 
        oddList  = new double[10], 
        evenList = new double[10];
    int negSz = 0, oddSz = 0, evenSz = 0;

    for(int i = 0; i < masterArray.length; i  ) {
        double z = masterArray[i];
        
        if (z < 0) {
            if (negSz < negList.length) {
                negList[negSz  ] = z;
            }
        }
        if (z % 2 == 0) {
            if (evenSz < evenList.length) {
                evenList[evenSz  ] = z;
            }
        } else if (oddSz < oddList.length) {
            oddList[oddSz  ] = z;
            sum  = z;
        }
    }
    if (negSz  < 10) negList  = Arrays.copyOf(negList,  negSz);
    if (oddSz  < 10) oddList  = Arrays.copyOf(oddList,  oddSz);
    if (evenSz < 10) evenList = Arrays.copyOf(evenList, evenSz);

    System.out.println("The numbers in the odd list are: "   Arrays.toString(oddList)   "; sum = "   sum);
    System.out.println("The numbers in the negative list are: "   Arrays.toString(negList));
    System.out.println("The numbers in the even list are: "   Arrays.toString(evenList)   "\n");
}

標籤：爪哇 数组 for循环

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