When I use std::string and when char* to manage arrays of chars in C++? It seems you should use char* if performance(speed) is crucial and you're willing to accept some of a risky business because of the memory management. Are there other scenarios to consider? ...
I'm starting to learn C by reading K&R and going through some of the exercises. After some struggling, I was finally able to complete exercise 1-19 with the code below: /* reverse: reverse the character string s */ void reverse(char s[], int slen) { char tmp[slen]; int i, j; i = 0; j = slen - 2; /* skip '\0' and \n */ tm...
I'm looking through some code for learning purposes. I'm working through this portion of code. // e.g. const unsigned char data={0x1,0x7C ... } unsigned char buf[40]; memset(buf,0,40); buf[0] = 0x52; memcpy(buf+1, data, length); // What does buf+1 do in this situation? On the last line where memcpy is called what does buf+1 do? buf is...
char *funcNames[]= {"VString","VChar","VArray","VData"}; for(int i=0;i<4;i++) { char* temp = funcNames[i]; int len = strlen(funcNames[i]); for(int j = 0;j<len ;j++) { if(j!=0) { char arr = temp[j]; } } } here i want to separate "V" from all string in char array ...and create a...
How do I write the MAC address ff:ff:ff:ff:ff:ff as a char[] in C? Do I just do char macaddress[6] = "%0xFF%0xFF%0xFF%0xFF%0xFF%0xFF"; I'm not sure. Thanks! ...
Hi, I've written a small program for my programming class, that uses pointers to reverse a char array. I was wondering if there is anything that I should do differently? Am I doing this correctly? Is there a more efficient way to accomplish this? Thanks! My small program: int main ( ) { char buffer[80]; PrintHeader(); cout << "\nStr...
Hi there, I'm writing a string tokenization program for a homework assignment in C++, that uses pointers. However, when I run & debug it, it says that my pointer pStart, is invalid. I have a feeling that my problem resides in my param'ed constructor, I've included both the constructor and the object creation below. I would appreciate it...
I have a a char array: char* name = "hello"; I want to add an extension to that name to make it hello.txt How can I do this? name += ".txt" won't work ...
Hi, I just wrote a program that tokenizes a char array using pointers. The program only needed to work with a space as a delimiter character. I just turned it in and got full credit, but after turning it in I realized that this program only worked if the delimiter character was a space. My question is, how could I make this program wor...
I have a char array which contains null characters at random locations. I tried to create an iStringStream using this array (encodedData_arr) as below, I use this iStringStream to insert binary data(imagedata of Iplimage) to a MySQL database blob field(using MySQL Connector/C++'s setBlob(istream *is) ) it only stores the characters upt...
I'm trying to check whether or not the second argument in my program is a substring of the first argument. The problem is that it only work if the substring starts with the same letter of the string. EDIT: It must be done in C, not C++. Sorry int main(int argc, char **argv){ if (argc != 3) { printf ("Usage: check <string o...
Simple question, how does one create a function which takes an unsigned char std::vector and spits out an unsigned char[] with a length. Thanks! Ah, well it seems my problem was my knowledge of std::vector. I always believed that std::vector did not hold its values in linear fashion. That solves a lot of my problems. Thanks! ...
Hi, I wanna to write something to a .txt file in .c file, but required to name that file with the current timestamp as the postfix, just like filename_2010_08_19_20_30. So I have to define the filename char array first and process the filename by myself?Assign the character one by one? Is there any easy way to do that? ...
I have this structure: class Base { public: void doACopy(char* strToCopy) { strcpy(str, strToCopy); } private: char str[4]; }; class Derived : public Base { public: void doSomething() { char toCopy[4]; toCopy[0] = 'a'; toCopy[1] = 'b'; toCopy[2] = 'c'; Base::doACopy(toCopy); // is there a...
Do these two lines of code achieve the same result? If I had these lines in a function, is the string stored on the stack in both cases? Is there a strong reason why I should use one over the other, aside from not needing to declare the null terminator in the first line of code? char s[] = "string"; char* s = "string\0"; ...