java - 总结Java中的每一行和每一列

Question

/*
 * Programmer: Olawale Onafowokan
 * Date: February 6, 2014
 * Purpose: Prints the row and column averages
 */
class Lab4 {
    public static void main(String[] args) {
        int [][] scores = {{ 20, 18, 23, 20, 16 },
            { 30, 20, 18, 21, 20 },
            { 16, 19, 16, 53, 24 },
            { 25, 24, 22, 24, 25 }};
        outputArray(scores);
    }

    public static void outputArray(int[][] array) {
        int sum= 0;
        int rowSize = array.length;
        int columnSize = array[0].length;
        System.out.println("rows=" + rowSize + "cols=" + columnSize);

        for (int i = 0; i < array.length; i++) {
            for (int j = 0; j < array[0].length; j++) {
                sum += array[i][j];
            }
            System.out.println("Print the sum of rows = " + sum);
        }
        for (int i = 0; i < array.length; i++) {
            sum = 0;
            sum = sum + array[i][j];
            // It is telling me the j can't be resolved
        }
    }
}

程序打印出:

rows=4cols=5
Print the sum of rows = 612
Print the sum of rows = 20358
Print the sum of rows = 652058
Print the sum of rows = 20866609

我不明白为什么它没有正确地添加数字。我正在尝试将每一行和每一列相加。我什至不确定这些数字是从哪里来的。

Answer 1

这是你的问题:

sum += sum + array[i][j];

sum += sum + array[i][j] 与 sum = sum + sum + array[i][j] 相同(你加了两次 sum)

应该是:

sum = sum + array[i][j]; 或者 sum += array[i][j];

如果您只想打印每个行的总和，请将您的sum重置为0，以便在外部上进行每次迭代-循环

for (int i = 0; i < array.length; i++){
    sum=0;
    ....  

如果你只想打印每个列的总和，你需要添加:

int[] colSum =new int[array[0].length];  

然后在 for-loop 中，添加

colSum[j]+=array[i][j]; 

最后你会得到这个:

int[] colSum =new int[array[0].length];
for (int i = 0; i < array.length; i++){   
    for (int j = 0; j < array[i].length; j++){                
        sum += array[i][j];
        colSum[j] += array[i][j];
    }
    System.out.println("Print the sum of rows =" + sum);
}  
for(int k=0;k<colSum.length;k++){
    System.out.println("Print the sum of columns =" + colSum[k]);
}