Warning: statement has no effect
Line 15
I have to display all the characters from s1 who are found in s2, too.
#include <iostream>
#include <string.h>
#include <ctype.h>
using namespace std;
int main()
{
char s1[250], s2[250];
unsigned int i;
cin.get(s1,250);
cin.get();
cin.get(s2,250);
for(i=0;i<strlen(s2);i++)
tolower(s2[i]);
for(i=0;i<strlen(s1);i++)
if(strchr(s2,tolower(s1[i])))
cout<<s1[i];
return 0;
}
std::tolower takes it's argument by value and returns the result, and therefore doesn't modify the input value.
Related
#include <iostream>
#include <time.h>
#include <string.h>
#include <stdio.h>
int main()
{
string msg;
printf("Enter the message that you wish to display as scroller: ");
getline(cin,msg);
msg=msg+". ";
int x=0;
while(1)
{
Scroll(msg);
wait(100);
system("cls");
x++;
}
cin.get();
return 0;
}
I Have this C code and all strings in the file say 'identifier "string" is undefined'. I tried including <string> instead of <string.h> but it didn't work. Why is it not working?
Add
using namespace std;
After includes (but before main). Or, better, use notion of:
std::string // instead of string
Update: I missed the point of this being C-question. I will leave this answer, but for the sake of formality, use it if you came from Google and you are working with C++.
This is C++ code, not C.
The compiler is probably getting confused because it cannot parse it, so then it finds C-like code and all identifiers do not exist.
The includes should be:
#include <iostream>
#include <ctime>
#include <string>
#include <cstdio>
You are also missing a:
using namespace std;
Plus the definitions for Scroll and wait etc.
Currently going thru a c++ course.
I had to create a word cipher using the strings: alphabet and key.
to cipher an inputted word with less code as possible I created this solution that gives the error:
no matching function for call to std::basic_string<char>::find(std::string&, int&, int)
I don't know how to solve it, neither do I know if my idea would work at all, would LOVE some help.
Thanks for your attention :)
#include <iostream>
#include <cstring>
#include <string>
using namespace std;
int main() {
string alphabet {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string key {"XZNLWEBGJHQDYVTKFUOMPCIASRxznlwebgjhqdyvtkfuompciasr"};
string word_to_encrypt {};
getline (cin,word_to_encrypt);
for (int i=0;i<word_to_encrypt.size;i++){
word_to_encrypt.replace (i,1,key,(alphabet.find(word_to_encrypt,i,1)),1);
}
cout<< word_to_encrypt;
}
Two problems:
First size is a function and not a variable. Therefore you need size().
Secondly std::string::find() has no overload which takes a std::string and two ints: https://en.cppreference.com/w/cpp/string/basic_string/find , but you can use the overload which takes a CharT instead by adding .c_str() or .data().
This compiles at least:
#include <iostream>
#include <cstring>
#include <string>
using namespace std;
int main() {
string alphabet {"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"};
string key {"XZNLWEBGJHQDYVTKFUOMPCIASRxznlwebgjhqdyvtkfuompciasr"};
string word_to_encrypt {};
getline (cin,word_to_encrypt);
for (int i=0;i<word_to_encrypt.size();i++){
word_to_encrypt.replace(i, 1, key, (
alphabet.find(word_to_encrypt.c_str(), i, 1)),1);
}
cout<< word_to_encrypt;
}
Here is the code
#include "stdafx.h"
#include <string>
#include <clocale>
#include <stdio.h>
#include <cstdlib>
using namespace std;
int souls;
void userInput(char situation[20]) {
if (situation == "souls") {
scanf("%i", souls);
printf("%i", souls);
}
}
void main() {
setlocale(LC_CTYPE, "rus");
userInput("souls");
system("pause");
}
It brakes after I input something in my scanf() (trying to change a global int) via the console (int number for example) and drops me into an "unhandled exception"
Why is it so? I am using MS Visual Studio 2005.
In your code
scanf("%i", souls);
should be
scanf("%i", &souls);
^
scanf() needs a pointer to type as the argument to store the scanned value corresponding to the supplied format specifier.
That said, if (situation=="souls") is wrong, too. You cannot compare the contents of strings using the == operator. You need to use strcmp() for that.
Your code has several issues:
You cannot compare C strings this way: if (situation == "souls"): you are comparing the addresses of the char arrays, not their contents. You need to use strcmp (and include <cstring>) for this:
if (!strcmp(situation, "souls"))
The signature void userInput(char situation[20]) is confusing: the size 20 information is ignored and your are actually passing the address of a shorter string literal, this signature would be more appropriate:
void userInput(const char *situation)
You need to pass the address of the output variable to scanf and check the return value: scanf("%i", souls); invokes undefined behavior, it should be changed to:
if (scanf("%i", &souls) == 1) {
/* souls was assigned a value */
} else {
/* scanf failed to parse an integer */
}
The signature for main should not be void main(), it should be either:
int main()
or
int main(int argc, char *argv[])
I'm using C++ in Microsoft Visual Studio 12. I want to pass command line arguments. I have tried listing them in the MSVS's Project/Properties/Debugging/Command Arguments field and I've also tried using the CLIArgsMadeEasy add on but it never works. argc is always 1 where, of course, argv[0] is the app path.
Example: given a program of fred.exe that I would like to launch with three args : a,b,c
i.e. the equivalent of a cmd window line of
fred.exe a b c
I specify the args in the provided edit boxes exactly as:
a b c
using either method described above (MSVS standard or CLIArgsMadeEasy) but when I run they aren't passed.
The code is:
#include <iostream> // for standard I/O
#include <string> // for strings
#include <iomanip> // for controlling float print precision
#include <sstream> // string to number conversion
#include <math.h>
using namespace std;
int main(int argc, char *argv[])
{
...
I have tried this program in my visual studio and it works:
#include <iostream> // for standard I/O
#include <string> // for strings
#include <iomanip> // for controlling float print precision
#include <sstream> // string to number conversion
#include <math.h>
using namespace std;
int main(int argc, char *argv[])
{
for(int i = 1; i < argc; i++)
{
cout << i << ":" << argv[i] << endl;
}
return 0;
}
I am working with C++ in eclipse CDT and I am trying to convert string to uint64_t by using strtoull but everytime I get below error message -
..\src\HelloTest.cpp:39:42: error: strtoull was not declared in this scope
Below is my C++ example
#include <iostream>
#include <cstring>
#include <string>
using namespace std;
int main() {
string str = "1234567";
uint64_t hashing = strtoull(str, 0, 0);
cout << hashing << endl;
}
return 0;
}
Is there anything wrong I am doing?
Why your solution doesn't work has already been pointed out by others. But there hasn't been a good alternative suggested yet.
Try this for C++03 strtoull usage instead:
#include <string>
#include <cstdlib>
int main()
{
std::string str = "1234";
// Using NULL for second parameter makes the call easier,
// but reduces your chances to recover from error. Check
// the docs for details.
unsigned long long ul = std::strtoull( str.c_str(), NULL, 0 );
}
Or, since C++11, do it directly from std::string via stoull (which is just a wrapper for the above, but saves on one include and one function call in your code):
#include <string>
int main()
{
std::string str = "1234";
// See comment above.
unsigned long long ul = std::stoull( str, nullptr, 0 );
}
Never use char[] or pointers if you have a working alternative. The dark side of C++, they are. Quicker, easier, more seductive. If once you start down the dark path, forever will it dominate your destiny, consume you it will. ;-)
the structure for strtoull is: strtoull(const char *, char * *, int)
You have given it a std::string as pointed out by #juanchopanza
This is the solution I came up with is
#include <iostream>
#include <cstring>
#include <string>
#include <cstdlib>
using namespace std;
int main() {
char str[] = "1234567";
unsigned long long ul;
char* new_pos;
charDoublePointer = 0;
ul = strtoull(str, &new_pos, 0);
cout << ul << endl;
return 0;
}
The output I got was: 1234567
Straight from the eclipse console.
Also at the end of your program you have return 0 out of scope with an extra curly brace.