总结在Java中每个行和列 [英] Summing up each row and column in Java

问题描述

/*
 * 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

我不明白为什么它不正确地加起来的数字。我试图加起来每行和每列。我甚至不知道在哪里，这些数字的来源。

I don’t understand why it isn't adding up the numbers correctly. I am trying to add up each row and column. I am not even sure where these numbers are coming from.

推荐答案

下面是你的问题：

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

之和+ = SUM +阵列[i] [j]的相同总和=总和+总和+阵列[I] [J ] （您添加总和的两倍的）

应该是：

总和=总和+阵列[I] [J]; 或 之和+ =阵列[我] [ J];

如果你要打印的每张行仅的总和，重置之到 0 有关外每次迭代 for循环

If you want to print the sum of each row only, reset your sum to 0 for each iteration on outer for-loop

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

如果你要打印的每张列仅的总和，需要补充一点：

If you want to print the sum of each column only, you need to add this:

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

然后在 for循环添加

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

所以最后你都会有这样的：

So finally you will have this:

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]);
} 

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