Question

我有这些结构：

typedef struct {
    char *start;
    char *loops;
    char *tolerance;
    double *numbers;
} configuration;

typedef struct {
    bool help;
    bool debug;
    const char *configFile;
    const char *inputFile;
    const char *outputFile;
    bool parallel;
    int fragmentSize;

} options;

当inputFile为NULL时，我将双指针（config.numbers）设置为数组：double numbers[] = {3,5,7};如果有inputFile我从中读取数字进入数组numberList之后我将指针config.numbers设置为numberList。这是代码：

//Safe number list into config
    if(opt.inputFile == NULL) {

        config.numbers = &numbers[0];
        lines = 3;
    } else {
        //Count lines|numbers in file
        FILE* fp;
        fp = fopen(opt.inputFile,"r");
        int bh = 0;
        while(!feof(fp))
        {
            bh = fgetc(fp);
            if(bh == '\n')
            {
                lines++;
            }
        }
        fclose(fp);
        //End counting

        //Read numbers from file
        fp = fopen(opt.inputFile,"r");
        double numberList[lines];
        double number;
        int n;
        for (n = 0; n < lines; n++) {
            fscanf(fp, "%lg", &number);
            numberList[n] = number;
        }
        //End reading numbers from file
        config.numbers = &numberList[0];

    }
    //End safing number list

当我使用此for循环在numberList中打印else时：

int z;
for(z = 0; z < lines; ++z) {
      printf("%f\n", numberList[z]));
}

一切正常，但是当我尝试使用带有for-Loop的指针打印数组时：

int z;
for(z = 0; z < lines; ++z) {
    printf("%f\n", *(config.numbers + z));
}

我得到的结果是这样的：

71861994.719069
28587064.020609
91127582.029965
34937973.383320
49643168.000000
0.000000
0.000000
27369248.460685
54686448.003485
93571557.380991
-nan
0.000000
0.000000
0.000000
0.000000
0.000000
0.000000

那么如何正确访问指针或者其他错误呢？

编辑：输入文件如下所示：

95181223.701304
27539279.045323
25701472.780528
29898009.416600
72366798.330269
3326112.825110
79857126.893409
38880807.039738
8199298.711586
42132873.992498
34763372.472843
14076941.001265
79042893.824653
17188914.128202
93208812.499982
42846886.181667
80882719.243356
23444107.325489

我期待相同的输出。

初始化行：

int lines = 0;

Answer 1

您已在else的{{1}}分支内声明了数组，然后尝试通过指针将其打印到该范围之外。这意味着当您尝试打印时，阵列已经被销毁。

您需要使用动态分配，或尝试重写代码，允许在要打印它的同一范围内声明/定义数组。

访问指向double数组的指针

1 个答案: