} } }

    C++ Primer 读书笔记 - 第三章

    添加时间:2013-5-20 点击量:

    1. std::string


        size()函数返回值为string::size_type,用下标时,也用string::size_type作为index的类型



    #include <iostream>
    
    #include
    <cstdio>
    #include
    <string>
    using namespace std;

    int main()
    {
    string s = abc;
    cout
    << s << endl;
    cin
    >> s;
    cout
    << s << endl;
    string line;
    while (getline(cin, line)) {
    if (line.empty())
    break;
    cout
    << line << endl;
    }
    string::size_type len = s.size();
    cout
    << len << endl;
    s[
    0] = toupper(s[0]);
    cout
    << s << endl;
    string s1;
    cout
    << s1[0] << endl;
    / string str = hello + world; / //error: two string literals addition is invalid
    return 0;
    }


    2. std::vector


        用push_back()函数插入元素,用下标不克不及用来插入元素,然则map可以,如map[key] = value就相当于把元素插入了。



    // an iterator that cannot write elements
    
    vector<int>::const_iterator

    // an iterator whose value cannot change
    const vector<int>::iterator //不克不及做it++


        再就是iterators在vector插入了新的元素后就会失效,然则std::list不会。



    #include <iostream>
    
    #include
    <vector>
    using namespace std;

    int main()
    {
    vector
    <int> vec(109);
    vector
    <int>::iterator it = vec.begin();
    it
    ++;
    cout
    << it << endl;
    vec.push_back(
    11);
    cout
    << it << endl;
    return 0;
    }



    #include <list>
    
    #include
    <iostream>
    using namespace std;

    int main()
    {
    list
    <int> mylist;
    mylist.push_back(
    1);
    mylist.push_back(
    2);
    mylist.push_back(
    3);
    mylist.push_back(
    4);
    list
    <int>::iterator it = mylist.begin();
    it
    ++;
    cout
    << it << endl;
    mylist.push_back(
    5);
    cout
    << it << endl;
    return 0;
    }


    3. std::bitset


        一种是用unsigned value进行初始化,一种是用字符串初始化,比如“0011”,那么bit[0] = str[3]



    容易发怒的意思就是: 别人做了蠢事, 然后我们代替他们, 表现出笨蛋的样子。—— 蔡康永
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