Question

public class chap7p4 {
    public static void main(String[] args) {
        int[] heights = { 33, 45, 23, 43, 48, 32, 35, 46, 48, 39, 41, };
        printArray(heights);
        System.out.println("Average is " + findAverage(heights)); // this is where I get the error
    }

    public static void printArray(int[] array) {
        for (int eachNum : array) {
            System.out.println(eachNum + "  ");
        }
    }

    public static void findAverage(int[] array) {
        int average = 0;
        int total = 0;
        for (int i = 0; i <= array.length; i++) {
            total = total + array[i];
        }
        average = total / array.length;
        System.out.println(average);

    }
}

我收到此错误

"Exception in thread "main" java.lang.Error: Unresolved compilation problem: The operator + is undefined for the argument type(s) String, void"

Answer 1

您的方法findAverage(heights)必须返回一个适用于二元运算符+的值，该运算符需要两个操作符。

Answer 2

更改findAverage()方法的返回类型

即void findAverage至int findAverage

public static int findAverage(int[] array) {
    int total = 0;
    for (int i = 0; i <= array.length; i++) {
        total = total + array[i];
    }
    return total / array.length;
}

Answer 3

你无法做到

String + void

findAverage方法返回void

Answer 4

Return类型的findAverage方法不应该为void，它应该是代码的整数。您不应该使用与在main方法中调用的方法相同的方法打印average的值。

Answer 5

findAverage具有void返回类型。更改方法的返回类型以返回int值

public static int findAverage(int[] array) {
 ...
 return total / array.length;
}

Answer 6

此处参数的类型为int，而类似（*，+，..）的运算符不适用于参数类型void和int，因此可以更改参数类型或返回类型，如上所述。

对于参数类型，未定义operator + String，void

6 个答案: