• c++从txt中读取数据,数据并不是一行路径(实用)


    #include <iostream>
    #include <fstream>
    #include <string>

    using namespace std;

    //输出空行
    void OutPutAnEmptyLine()
    {
    cout << " ";
    }

    //读取方式: 逐词读取, 词之间用空格区分
    //read data from the file, Word By Word
    //when used in this manner, we'll get space-delimited bits of text from the file
    //but all of the whitespace that separated words (including newlines) was lost.
    void ReadDataFromFileWBW()
    {
    ifstream fin("C:\Users\byte\Desktop\huang.txt");
    string s;
    while (fin >> s)
    {
    cout << "Read from file: " << s << endl;
    }
    }

    //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("C:\Users\byte\Desktop\huang.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("C:\Users\byte\Desktop\huang.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);
    }
    }


    int main()
    {
    ReadDataFromFileWBW(); //逐词读入字符串
    OutPutAnEmptyLine(); //输出空行

    ReadDataFromFileLBLIntoCharArray(); //逐词读入字符数组
    OutPutAnEmptyLine(); //输出空行

    ReadDataFromFileLBLIntoString(); //逐词读入字符串
    OutPutAnEmptyLine(); //输出空行

    ReadDataWithErrChecking(); //带检测的读取
    getchar();
    return 0;
    }

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  • 原文地址:https://www.cnblogs.com/byteHuang/p/7299566.html
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