尝试执行java函数时出错

Question

我创建了一个 java 函数来做一些计算。但我收到如下错误

Solution.java:#line_num: 错误：找不到符号 double a=count1/arr.length; ^ 符号：变量 count1 位置：类 解决方案 Solution.java:#line_num: 错误：找不到符号 double b=count2/arr.length; ^ 符号：变量 count2 位置：类 解决方案 Solution.java:#line_num: 错误：找不到符号 double c=count3/arr.length; ^ 符号：变量count3 位置：类 解决方案3 错误

作为我的代码，我从用户那里获取输入并将数据传递给函数。但我无法识别我们的问题。我在下面提到了我的功能

static void plusMinus(int[] arr) {

    for(int i=0;i<arr.length;i++){

        int count1=0;

        int count2=0;

        int count3=0;

        if(arr[i]>0){

            count1++;

        }

        else if(arr[i]<0){

            count2++;

        }

        else{

            count3++;

        }

    }

    System.out.println(count1/arr.length);

    System.out.println(count2/arr.length);

    System.out.println(count3/arr.length);

}

Answer 1

您已经在for 循环内部创建并初始化count1&nbsp;count2并count3在外部使用全局声明它以从任何地方访问它

Answer 2

尝试这个：您必须声明count1,count2并count3在 for 循环之外。static void plusMinus(int[] arr) {&nbsp; &nbsp; int count1=0;&nbsp; &nbsp; int count2=0;&nbsp; &nbsp; int count3=0;&nbsp; &nbsp; for(int i=0;i<arr.length;i++){&nbsp; &nbsp; &nbsp; &nbsp; if(arr[i]>0){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count1++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; else if(arr[i]<0){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count2++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; else{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count3++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; System.out.println(count1/arr.length);&nbsp; &nbsp; System.out.println(count2/arr.length);&nbsp; &nbsp; System.out.println(count3/arr.length);}

Answer 3

您需要声明3个变量，count1，count2和count3外面两个for回路，所以它们在函数内部可以访问任何地方。您可以在需要时在循环内初始化或更改它们的值。但是声明需要在外面完成。static void plusMinus(int[] arr) {&nbsp; &nbsp; &nbsp; &nbsp; int count1=0;&nbsp; &nbsp; &nbsp; &nbsp; int count2=0;&nbsp; &nbsp; &nbsp; &nbsp; int count3=0;&nbsp; &nbsp; for(int i=0;i<arr.length;i++){&nbsp; &nbsp; &nbsp; &nbsp; if(arr[i]>0){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count1++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; else if(arr[i]<0){&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count2++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; else{&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; count3++;&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp; &nbsp; System.out.println(count1/arr.length);&nbsp; &nbsp; System.out.println(count2/arr.length);&nbsp; &nbsp; System.out.println(count3/arr.length);}