如何为多维数组编写方法

Question

我想编写一个从Time数组中选择特定年份(比如2009年)的方法。

这将指(8001)，这基本上是2009年的一个关键。

在FactTable中，我想添加所有代表数量( 1s)的数字。因此，它将显示2009年的销售总额。任何人都能知道我是怎么做到的。

Time数组存储{timekey, year, month, week, day}

FactTable存储{clientid, Vehicleid, branchid, timekey, quantity, profit}

 int[][] Time = new int[][] 
        {{8001,2009,1,1,1},
        {8002,2010,1,1,7},
        {8003,2011,1,1,5},
        {8004,2012,1,1,5}};


int[][] FactTable = new int [][]
        {{1,125,20,8001,1,2000},
        {2,126,40,8001,1,1500},
        {3,127,50,8001,1,2500},
        {4,128,10,8001,1,2500}};

int sum = 0; 

int year = 8001;



for (int i = 0; i< FactTable.length-1; i++)
{
    for (int j = 1; j < FactTable[i].length-1; j++)
    {
        year = year + FactTable + [0][4];

    }

}
System.out.println (year); 

Answer 1

我希望这能帮到你

int year = 2009;
int timeKey = -1;

for (int array[] : Time) {
    if (array[1] == year) {
        timeKey = array[0]; 
        break;
    }
}

int sum = 0;

for (int array[] : FactTable) {
    if (array[3] == timeKey) {
        sum += array[4]; 
    }
}

System.out.println(sum);

Answer 2

下面的代码演示如何在多维数组中寻址字段

int sum = 0; 
int year = 8001;
for (int i = 0; i< FactTable.length; i++)
    {
       if (FactTable[i][3] == year) {
           sum = sum + FactTable[i][4];
       }
    }
System.out.println(sum);

请注意在for循环中第二个表达式的更正。

Answer 3

public class Test1 {

    public static void main(String[] args) {
        int[][] timeTable = new int[][] { { 8001, 2009, 1, 1, 1 },
                { 8002, 2010, 1, 1, 7 }, { 8003, 2011, 1, 1, 5 },
                { 8004, 2012, 1, 1, 5 } };
        int[][] factTable = new int[][] { { 1, 125, 20, 8001, 1, 2000 },
                { 2, 126, 40, 8001, 1, 1500 }, { 3, 127, 50, 8001, 1, 2500 },
                { 4, 128, 10, 8001, 1, 2500 } };
        meth(factTable, 2009, timeTable);
    }

    private static void meth(int[][] factTable, int year, int[][] timeTable) {
        int timeKey = -1;
        // find the timeKey from the year
        for (int[] is : timeTable) { // for each row in timeTable
            if (is[1] == year) { // if the year column (duh) is the year
                timeKey = is[0]; // get the timekey
                break; // we're done
            }
        }
        if (timeKey == -1) return; //timeKey still -1: no timeKey for year
        int sum = 0;
        for (int[] js : factTable) { // for each row in factTable
            if (js[3] == timeKey) { // if the timeKey column is right
                sum += js[4]; // add to the sum the quantity
            }
        }
        System.out.println(sum); // done
    }
}

虽然我真的不知道这些数组是为了什么