ostream

Replace line in txt file c++

由 早过忘川 提交于 2020-01-03 05:05:35
问题 I just wondering cause i have a text file containing STATUS:USERID:PASSWORD in accounts.txt example it would look like this: OPEN:bob:askmehere: OPEN:john:askmethere: LOCK:rob:robmypurse: i have a user input in my main as such user can login 3x else status will change from OPEN to LOCK example after 3 tries of john before: OPEN:bob:askmehere: OPEN:john:askmethere: LOCK:rob:robmypurse: after: OPEN:bob:askmehere: LOCK:john:askmethere: LOCK:rob:robmypurse: what i have done is: void lockUser

print address of array of char

由 假如想象 提交于 2020-01-02 07:50:49
问题 int *i = new int(1); cout << i << endl; Will print the address of the integer. char *c="cstring"; cout << c << endl; cout << &(*c) << endl; Will both print "cstring". I guess this behavior can simply be explained with the implementation of ostream& operator<< (ostream& out, const char* s ); in the IOstream Library. But what to do if you actually want to print the address of the data c refers to? 回答1: cout << reinterpret_cast<void*>(c) << endl; or just cout << (void*)c << endl; 回答2: Try

如何生成静态页

由 对着背影说爱祢 提交于 2020-01-01 21:25:35
如何生成静态页: 方案1： /// <summary> /// 传入URL返回网页的html代码 /// </summary> /// <param name="Url">URL</param> /// <returns></returns> public static string getUrltoHtml(string Url) { errorMsg = ""; try { System.Net.WebRequest wReq = System.Net.WebRequest.Create(Url); // Get the response instance. System.Net.WebResponse wResp =wReq.GetResponse(); // Read an HTTP-specific property //if (wResp.GetType() ==HttpWebResponse) //{ //DateTime updated =((System.Net.HttpWebResponse)wResp).LastModified; //} // Get the response stream. System.IO.Stream respStream = wResp.GetResponseStream(); // Dim reader As

生成静态网页的几种方法

由 夙愿已清 提交于 2020-01-01 21:24:11
如何生成静态页： 方案1： /// <summary> /// 传入URL返回网页的html代码 /// </summary> /// <param name="Url">URL</param> /// <returns></returns> public static string getUrltoHtml(string Url) { errorMsg = ""; try { System.Net.WebRequest wReq = System.Net.WebRequest.Create(Url); // Get the response instance. System.Net.WebResponse wResp =wReq.GetResponse(); // Read an HTTP-specific property //if (wResp.GetType() ==HttpWebResponse) //{ //DateTime updated =((System.Net.HttpWebResponse)wResp).LastModified; //} // Get the response stream. System.IO.Stream respStream = wResp.GetResponseStream(); // Dim reader As

ostream cout and char *

由 柔情痞子 提交于 2019-12-31 05:11:31
问题 I have an array of chars like this one: char arr[3]="hi"; cout << arr;// this will print out hi So is the operator<< has an overloaded version that takes an ostream object and char *. so cout<<arr; first arr will decays to a chat * . and then operator<<() will print out what the char pointer is pointing to until it find a null-character ? The same question for cin>>arr; how does it work with operator>> that takes an array as the second operand. 回答1: Your ostream and istream do have operator<<

How to make C++ cout not use scientific notation

由 ♀尐吖头ヾ 提交于 2019-12-27 14:46:14
问题 double x = 1500; for(int k = 0; k<10 ; k++){ double t = 0; for(int i=0; i<12; i++){ t += x * 0.0675; x += x * 0.0675; } cout<<"Bas ana: "<<x<<"\tSon faiz: "<<t<<"\tSon ana: "<<x+t<<endl; } this the output Bas ana: 3284.78 Son faiz: 1784.78 Son ana: 5069.55 Bas ana: 7193.17 Son faiz: 3908.4 Son ana: 11101.6 Bas ana: 15752 Son faiz: 8558.8 Son ana: 24310.8 Bas ana: 34494.5 Son faiz: 18742.5 Son ana: 53237 Bas ana: 75537.8 Son faiz: 41043.3 Son ana: 116581 Bas ana: 165417 Son faiz: 89878.7 Son

Dynamic Array Template Class: problem with ostream& operator friend function

由 痞子三分冷 提交于 2019-12-25 17:25:31
问题 Hi there fellow computer scientists, I'm having a lot of issues with my code, everything works except for the friend ostream& operator function. I keep getting a compiler error when sending my class object to cout. I'm thinking a made an error while declaring the friend function or maybe within its declaration.Here is the code: By the way I know its traditional to use T for templates but I used my professors name, it sounds weird but using unconventional names in my code helps me remember

Modify contents of basic_ostream object in c++ or, deleting data contents of basic_ostream object

由 倖福魔咒の 提交于 2019-12-25 16:27:32
问题 I get a ostream object reference in a function. It contains a string which I need to modify. I copied the contents of the ostream using rdbuf() function into a stringstream . Now I need to copy the updated stringstream (the underlying string that is) back to the ostream object. How can I do this? I searched ways of erasing the contents of the ostream, but could not find one. Note: I cannot change the implementation of other functions, i.e., I an unable to use ostringstream (which I know can

C++: Reading Data and Outputting Data

由 喜你入骨 提交于 2019-12-25 15:52:13
问题 I'm attempting to write two methods. One, ReadData(istream&) to read in student's ID number, first and last names, 10 program scores, and midterm and exam scores(last two integers) and returns true if all data was read successfully, false otherwise, and one, WriteData(ostream&) to write the data that was read in to a new file in the same order listed above. I am completely new to file reading and writing so any and all help is much appreciated. The data I am using looks like this...(made up

Compiler not creating templated ostream << operator

由 心已入冬 提交于 2019-12-23 21:04:03
问题 I have a class, defined in a head as: template <typename T> class MyClass { template <typename U> friend std::ostream& operator<<(std::ostream& output, const MyClass<U>& p); public: ... } In an implementation file, I have: template <typename U> std::ostream& operator<<(std::ostream& output, const MyClass<U>& m) { output << "Some stuff"; return output; } Which all looks fairly kosher. However, when I try and use this operator (i.e. std::cout << MyClass()), I get the following linker error:
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