C++ 简单读写文本文件、统计文件的行数、读取文件数据到数组（2）

//读取方式: 逐行读取, 将行读入字符数组, 行之间用回车换行区分
//If we were interested in preserving whitespace,
//we could read the file in Line-By-Line using the I/O getline() function.
void ReadDataFromFileLBLIntoCharArray()
{
    ifstream fin("data.txt");
    const int LINE_LENGTH = 100;
    char str[LINE_LENGTH]; 
    while( fin.getline(str,LINE_LENGTH) )
    {   
        cout << "Read from file: " << str << endl;
    }
}

//读取方式: 逐行读取, 将行读入字符串, 行之间用回车换行区分
//If you want to avoid reading into character arrays,
//you can use the C++ string getline() function to read lines into strings
void ReadDataFromFileLBLIntoString()
{
    ifstream fin("data.txt"); 
    string s; 
    while( getline(fin,s) )
    {   
        cout << "Read from file: " << s << endl;
    }
}

//带错误检测的读取方式
//Simply evaluating an I/O object in a boolean context will return false
//if any errors have occurred
void ReadDataWithErrChecking()
{
    string filename = "dataFUNNY.txt"; 
    ifstream fin( filename.c_str()); 
    if( !fin )
    {  
        cout << "Error opening " << filename << " for input" << endl;  
        exit(-1); 
    }
}