C 程序 - 验证从文本文件中读取的数字

Question

我正在从一个文本文件中读取 15 个数字，每个数字在一个新行中:

1234510121314152122232426

As you can see from the code I need the numbers to be validated so they are less than 26, otherwise terminate the program.

At the moment I am validating only after inserting it to the array (numArray). Is there a cleaner way of doing it (to validate before inserting to the array)?

The problem is, I can't seem to get the actual line in the text file that's being read. That's why I've validated it using the loop index on the array (int x = numArray[i];).

Any help is appreciated, I'm quite new to C programming. Thanks.

FILE *myFile = fopen(dataset.txt, "r");
int numArray[15];

if (myFile != NULL) {

    for (int i = 0; i < sizeof(numArray); i++)
    {
        //insert int to array
        fscanf(myFile, "%d", &numArray[i]);

        //Validate number
        int x = numArray[i]; 
        if (x > 25) {
            printf("Invalid number found, closing application...");
            exit(0);
        }
    }

    //close file
    fclose(myFile); 
}
else {
    //Error opening file
    printf("File cannot be opened!");
}

Answer 1

当然你可以把它存储在一个局部变量中，只有在有效时才赋值。但是由于您正在调用 exit(0) 如果无效，它不会改变任何东西。我想你想从循环中break。

顺便说一句，你的循环是错误的。你必须将 sizeof(numArray) 除以一个元素的大小，否则你会循环太多次，如果你的输入文件中有太多数字，你会崩溃机器(是的，我还添加了文件结束测试)

if (myFile != NULL) {

    for (int i = 0; i < sizeof(numArray)/sizeof(numArray[0]); i++)
    {
        int x; 
        //insert int to array
        if (fscanf(myFile, "%d", &x)==0)
        {
            printf("Invalid number found / end of file, closing application...\n");
            exit(0);  // end of file / not a number: stop
        }

        //Validate number
        if (x > 25) {
            printf("Invalid number found, closing application...\n");
            exit(0);
        }
        numArray[i] = x;
    }

    //close file
    fclose(myFile); 
}