char

Typcast a null pointer to char*

Suppose I have a char* elem that is supposed to hold a char**, such that elem[0] = char**, elem[1...m]= <more chars>. Is there a way I can put a null ptr within char* elem? When I try to set elem = NULL, it gives me a type error because NULL is an int. Any help would be greatly appreciated! ...

Char* vs std::string

Possible Duplicate: C++ char* vs std::string Is there any advantage to using char*'s instead of std::string? I know char*'s are usually defined on the stack, so we know exactly how much memory we'll use, is this actually a good argument for their use? Or is std::string better in every way? ...

C++ Char without Limit

I'm pretty well versed in C#, but I decided it would be a good idea to learn C++ as well. The only thing I can't figure out is chars. I know you can use the string lib but I also want to figure out chars. I know you can set a char with a limit like this: #include <iostream> using namespace std; int main() { char c[128] = "limited ...

Char * reallocation in C++

Hi, I need to store a certain amount of data in the "char *" in C++, because I want to avoid std::string to run out of memory, when exceeding max_size(). But the data comes in data blocks from the network so I need to use reallocation every time I get the data block. Is there any elegant solution for char * reallocation and concatenatio...

How do I output an individual character when using char *[] = "something"

I've been playing with pointers to better understand them and I came across something I think I should be able to do, but can't sort out how. The code below works fine - I can output "a", "dog", "socks", and "pants" - but what if I wanted to just output the 'o' from "socks"? How would I do that? char *mars[4] = { "a", "dog", "sock", "...

Best way to handle storing (possibly NULL) char * in a std::string

class MyClass { public: void setVar(const char *str); private: std::string mStr; int maxLength; //we only store string up to this length }; What's the best approach to implement setVar when the external code is quite likely to pass in NULL for an empty string (and cannot be changed)? I currently do something a bit like: void M...

Why is passing a string literal into a char* argument only sometimes a compiler error?

I'm working in a C, and C++ program. We used to be compiling without the make-strings-writable option. But that was getting a bunch of warnings, so I turned it off. Then I got a whole bunch of errors of the form "Cannot convert const char* to char* in argmuent 3 of function foo". So, I went through and made a whole lot of changes to fix...

Deleting dynamic array of char in C++.

I have this class, with the atribute 'word' class Node { char *word; Inside the Node constructor, I do this asignation: word = new char[strlen(someword)]; In the destructor of the Node class, I try to delete the contents pointed by word: delete []word; I obtain the next message after executing the programs: "Heap block ...

SVN 255 Character Problem

Hi Guys, I am using TortiseSVN and we have a problem when we exporting etc because subversion errors. The path has a character limit 255 - so I am not sure if this is the problem [I think it is in Win7 x-64 bit] How do I fix this ? i.e. allow paths for >255 characters ? ...

Getting a cryptic error on my simple Java program, comparing char[i] to a string.

public static void ejemplosString(String palabra){ char[] letras = palabra.toCharArray(); int contadorVocales = 0; for (int i = 0; i < letras.length; i++) { if (char[i] == 'a') { contadorVocales++; } if (char[i] == "e") { ...

Count max rectangles number, that can be placed inside character

Hi, I need a solution for quite complex problem. Exactly, I need to calculate the number of rectangles that can be placed inside letter/character with given size, considering that all rectangles are the same size, but it(the size) and the letter/character(of some regular specific font) itself can be changed by user(this will be used as w...

Using strncat with char array element in C

Hi.. I have get error with the following code and i can't figure it out. char name[]="tolgahan" char result[100]=""; strncat(result,name[1],1); I guess, i need to convert name[1] to string format but i don't now how can i do that. Please help me. Best regards. ...

fill a buffer successively

i intend to fill a char-pointer array successively in a for-loop. the content to fill in is a integer so i need to cast. but i didn't get the result i want to.. for (i=0;i<max0;i++){ sprintf(buf, "%d", content[i]); } sprintf replaces the hole buf, but i want to append. for (i=0;i<max0;i++){ buf[i]=(char) contint[i] } but th...

How to generate a random String in Java

Hi everyone, I have an object called Student, and it has studentName, studentId, studentAddress, etc. For the studentId, i have to generate random string consist of seven numeric charaters, eg. studentId = getRandomId(); studentId = "1234567" <-- from the random generator. and i have to make sure that there is no duplicate id. than...

What's the deal with char.GetNumericValue?

I was working on Project Euler 40, and was a bit bothered that there was no int.Parse(char). Not a big deal, but I did some asking around and someone suggested char.GetNumericValue. GetNumericValue seems like a very odd method to me: Takes in a char as a parameter and returns...a double? Returns -1.0 if the char is not '0' through '9...

How to compare characters (respecting a culture)

For my answer in this question I have to compare two characters. I thought that the normal char.CompareTo() method would allow me to specify a CultureInfo, but that's not the case. So my question is: How can I compare two characters and specify a CultureInfo for the comparison? ...

how to pass vector of string to foo(char const *const *const)?

Edit: Thank you all very much for your help. Now I feel that I'm really stupid and I am so sorry to waste your time. After implementing James Hopkin' suggestion, I still get the warnings of "invalid name 'null'", which is much better than those weird characters. Then, I went back and read the library document again, and it turns out that...

Why does this C++ char array seem to be able to hold more than its size?

#include <iostream> using namespace std; typedef struct { char streetName[5]; } RECORD; int main() { RECORD r; cin >> r.streetName; cout << r.streetName << endl; } When I run this program, if I enter in more than 5 characters, the output will show the whole string I entered. It does not truncate at 5 characters. Why...

How to copy a string into a char array in C++ without going over the buffer

I want to copy a string into a char array, and not overrun the buffer. So if I have a char array of size 5, then I want to copy a maximum of 5 bytes from a string into it. what's the code to do that? ...

How to make a copy of a char and not a reference in C++

If I declare a function like this: string hash (char* key) then any change I make to key will also change it's value when the function exits, correct? I want to make a copy of it in the function so that I can safely change it without changing the original value. I tried this, but it doesn't work. char temp = key; How can it be do...