欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  移动技术

15

程序员文章站 2022-08-28 11:37:16
ios类定义了这四个常量badbit, eofbit, failbit, goodbit这四个标志常量就是取对应标志位的掩码,也即输入的四种异常情况!以上四个常量对应的取值为:ios::badbit 001 输入(输出)流出现致命错误,不可挽回ios::eofbit 010 已经到达文件尾ios::failbit 100 输入(输出)流出现非致命错误,可挽回ios::goodbit 000 流状态完全正常, 各异常标志位都为0就一般说来,badbit是一些系...

ios类定义了这四个常量badbit, eofbit, failbit, goodbit
这四个标志常量就是取对应标志位的掩码,也即输入的四种异常情况!
以上四个常量对应的取值为:
ios::badbit 001 输入(输出)流出现致命错误,不可挽回
ios::eofbit 010 已经到达文件尾
ios::failbit 100 输入(输出)流出现非致命错误,可挽回
ios::goodbit 000 流状态完全正常, 各异常标志位都为0
就一般说来,badbit是一些系统底层或者硬件出错,比如文件系统错误,磁盘错误,网络错误等等。failbit就是其他软件错误,如试图从不能解析为整数的字符串里想要读一个整数等,顺便说下eof也会造成failbit被置位。

//以上转载于百度知道
首先建立 fish.text文件, 存入数据:18 19 18.5 13.5 14 16 19.5 20 18 12 18.5 17.5

	const int SIZE = 20;
	char filename[SIZE];
	ifstream inFile;
	cout << "enter the filename: ";
	cin.getline(filename, SIZE);
	inFile.open(filename);//输入fish.text

	if (!inFile.is_open())
	{
		cout << "can not open the file! " << endl;
		exit(EXIT_FAILURE);
	}

	double value;
	double sum = 0.0;
	int count = 0;

	inFile >> value;
	while (inFile.good())//while input good and not at EOF
	{
		++count;
		sum += value;
		cout << value << endl;
		inFile >> value;
	}
	if (inFile.eof())
		cout << "End of file reached.\n";
	else if (inFile.fail())
		cout << "input terminated by data mismatch.\n";
	else
		cout << "input terminated for unknown reason.\n";

	if (count == 0)
		cout << "No data processed.\n";
	else
	{
		cout << "items read:" << count << endl;
		cout << "sum: " << sum << endl;
		cout << "Average: " << sum / count << endl;
	}

	inFile.close();

本文地址:https://blog.csdn.net/qq_44886707/article/details/107204801