Java 通过多种方法传递二维数组

我为学校写的程序有点麻烦。本质上，我必须使用多种方法并通过它们传递二维数组。为此，我必须在方法中使用嵌套for循环，但这些方法不允许我返回“total”。你可以在下面看到我使用的方法。下面两种方法运行良好，只有那些带有总变量的方法不行。（是的，我试过用其他名字。）

//每行的方法和
公共静态int行和（int[][]矩阵）{
System.out.println（“行总数**********************************************”；
对于（int row=0；row问题在于变量范围，
你的代码在这些地方有缺陷

public static int columnsum(int[][] matrix){
System.out.println("Column Totals************************************");
for (int column = 0; column<matrix[0].length; column++){
    int total = 0; // total is defined within the for loop you cannot access it outside the for loop
    for (int row = 0; row<matrix.length; row++){
        total += matrix[row][column];
    System.out.println("The sum of column "+column+" is: "+total);
    }
return total; // Java do not know the total variable since it's already got destroyed after the for loop got terminated
}

公共静态int-columnsum（int[][]矩阵）{
System.out.println（“列总计*************************************************”；
for（int column=0；column
total
变量仅在for循环内部可见。在循环外部定义它们。可能重复
public static int columnsum(int[][] matrix){
System.out.println("Column Totals************************************");
for (int column = 0; column<matrix[0].length; column++){
    int total = 0; // total is defined within the for loop you cannot access it outside the for loop
    for (int row = 0; row<matrix.length; row++){
        total += matrix[row][column];
    System.out.println("The sum of column "+column+" is: "+total);
    }
return total; // Java do not know the total variable since it's already got destroyed after the for loop got terminated
}

public static int columnsum(int[][] matrix){
System.out.println("Column Totals************************************");
int total = 0; // define total here
for (int column = 0; column<matrix[0].length; column++){

    for (int row = 0; row<matrix.length; row++){
        total += matrix[row][column];
    System.out.println("The sum of column "+column+" is: "+total);
    }
return total;
}