I want to print two strings (say "ABC" and "DEF") with 5 space characters before "ABC" and that the second string will start 7 characters after the beginning of the first string.
I suspect you're looking for the width() method:
#include <iostream>
#include <string>
using namespace std;
int main()
{
string abc = "ABC";
string edf = "EDF";
cout.width(8);
cout << abc;
cout.width(7);
cout << edf;
return 0;
}
#include <cstdio>
#include <cstdlib>
#include <iostream>
using namespace std;
int main()
{
char a[] = "ABC";
char b[] = "EDF";
cout<" "<<a<<" "<<b;
return 0;
}
Related
I would like to print the strings at the top of columns with a 1 x 3 array.
I have edited this simple function several times, and this produces the least errors. New to C++, reading Deital Chap 6 Recursive.
What am I missing? I started with half brackes around strings, and brackets seemed to produce less errors.
Here is the code:
#include <iostream>
#include <string>
#include <array>
using namespace std;
int main() {
array a[1][3] = ["Car" "Hours" "Charge"]
cout<< a << endl;
}
Terminal produces errors as such:
parking_charges_6_12.cpp: In function ‘int main()’:
parking_charges_6_12.cpp:8:7: error: missing template arguments before ‘a’
8 | array a[1][3] = ["Car" "Hours" "Charge"]
^
This should work:
#include <array>
#include <iostream>
#include <string>
int main(){
std::array<std::string, 3> headlines = {"Car", "Hours", "Charge"};
for( auto const& elem : headlines ){
std::cout << elem << "\t";
}
}
It should be curly braces {} in the initializer, not []. And you need a comma between each element.
On the other hand, in later C++ revisions array can detect the type and number of elements, so you don't have to give that.
#include <iostream>
#include <array>
using namespace std;
int main() {
array a = {"Car", "Hours", "Charge"};
for (auto& item : a)
cout<< item << endl;
}
How about something like this:
#include<iostream>
using namespace std;
int main() {
string data[3] = {"Car", "Hours", "Charge"};
for (int i = 0; i < 3; i++)
cout << data[i] << " ";
}
Obviously it is not using the array header, but it's a working example. If you do need to use the array header, you can try something like :
#include <array>
#include <iostream>
#include <iterator>
#include <string>
using namespace std;
int main() {
array<string, 3> ar3 = {"Car", "Hours", "Charge"};
cout << ar3.size() << endl;
for (auto i : ar3)
cout << i << ' ';
return 0;
}
You can see it working online here
this is my code
the error is Segmentation fault,and i can't understand why
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;
int main(int argc, char* argv[])
{
char* szword[100];
int i = 0;
do
{
cin >> szword[i];
cout << szword[i];
i++;
}while(strcmp(szword[i - 1], "done"));
cout << i + 1;
return 0;
}
For starters neither declaration from headers <cstdio> and <string> is used in your program. So you should remove these directives
#include <cstdio>
#include <string>
You declared an initialized array with the element type char *. Thus this statement
cin >> szword[i];
invokes undefined behavior because the pointer szword[i] has indeterminate value.
Moreover this call even if the argument of the operator will be correct
cin >> szword[i];
can fail. You should check whether it was successful. And I think there is no great sense to output the string "done".
Also in this statement
cout << i + 1;
you are outputting a value that is greater than the number of inputted strings.
If to use character arrays then your program could look the following way
#include <iostream>
#include <cstring>
int main()
{
const size_t N = 100;
char szword[N][N];
size_t i = 0;
while ( std::cin.getline( szword[i], sizeof( szword[i] ) ) &&
std::strcmp( szword[i], "done" ) != 0 )
{
std::cout << szword[i++] << '\n';
}
std::cout << i << '\n';
return 0;
}
The program output might look like
Hello
World
2
This below code works fine, if you want to use char *, for C++ string you can use the C++ version
C Version:
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;
int main(int argc, char* argv[])
{
char *tmp;
int i = 0;
do
{
cin >> tmp;
cout << tmp;
i++;
}while(strcmp(tmp, "done"));
cout << i + 1;
return 0;
}
C++ Version:
#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
using namespace std;
int main(int argc, char* argv[])
{
string tmp;
int i = 0;
do
{
cin >> tmp;
cout << tmp;
i++;
}while(tmp != "done"));
cout << i + 1;
return 0;
}
We have a char. We need to replace all ab characters from our char with the letter c.
Example we have :
abracadabra
the output will be :
cracadcra
I tried to use replace() function from C++, but no success.
#include <iostream>
#include <cstring>
using namespace std;
int main()
{
string test;
cin>>test;
for(int i=0;i<(strlen(test)-1);i++)
{
if((test[i]=='a')&&(test[i+1]=='b')){
test.replace( test[i], 'c' );
test.replace( test[i+1] , ' ' );
}
}
cout << test << endl;
return 0;
}enter code here
You can use C++11 regex:
#include <iostream>
#include <regex>
#include <string>
int main() {
std::string str = "abracadabra";
std::regex r("ab");
std::cout << std::regex_replace(str, r, "c") << "\n"; // cracadcra
}
Problem:
That is not the syntax of std::string::replace.
Solution:
As is mentioned here the syntax is std::string::replace(size_t pos, size_t len, const string& str). Do test.replace(i, 2, "c" ) instead of test.replace(test[i],'c').
Or use regular expressions as dtell pointed.
Adittional information:
using namespace std; is considered a bad practice (More info here).
You should use std::string::size instead of strlen when you're working with std::string.
To work with std::string you should use #include <string> instead of #include <cstring>.
Full code:
#include <iostream>
int main()
{
std::string test;
std::cin >> test;
for(unsigned int i = 0; i < test.size() - 1; i++)
{
if((test[i]=='a') && (test[i+1]=='b'))
{
test.replace(i, 2, "c" );
}
}
std::cout << test << std::endl;
return 0;
}
The simplest thing you can do by using the standard library is first to find ab and then replace it. The example code I wrote is finding string ab unless there is None in the string and replacing it with c.
#include <iostream>
#include <string>
int main()
{
std::string s = "abracadabra";
int pos = -1;
while ((pos = s.find("ab")) != -1)//finding the position of ab
s.replace(pos, sizeof("ab") - 1, "c");//replace ab with c
std::cout << s << std::endl;
return 0;
}
//OUTPUT
cracadcra
Please explain why is this giving an error but the other on is running fine
The following code gives the error:
#include <iostream>
#include <string>
#include <conio.h>
#include <math.h>
#include <iomanip>
#include <string.h>
using namespace std;
int main()
{
string s1,s2;
int i;
cout << "Enter the string to copy into another string : ";
getline(cin,s1);
for(i=0; s1[i]!='\0'; ++i)
{
s2[i]=s1[i];
}
s2[i]='\0';
cout<<"\n\nCopied String S2 is : "<<s2;
return 0;
}
Error looks like this
But this works perfectly fine
#include <iostream>
#include <string>
#include <conio.h>
#include <math.h>
#include <iomanip>
#include <string.h>
using namespace std;
int main()
{
char s1[100], s2[100], i;
cout << "Enter the string to copy into another string : ";
cin>>s1;
for(i=0; s1[i]!='\0'; ++i)
{
s2[i]=s1[i];
}
s2[i]='\0';
cout<<"\n\nCopied String S2 is : "<<s2;
return 0;
}
In your case, s2 is initialized to an empty string with a length of 0, so you can't write past the bounds. If you want to, you must first resize it:
s2.resize(s1.length());
for(i=0; s1[i]!='\0'; ++i)
{
s2[i]=s1[i];
}
Also, c++ std::string does not need a terminating nullbyte, unlike C strings.
How can I get a substring of a std::wstring which includes some non-ASCII characters?
The following code does not output anything:
(The text is an Arabic word contains 4 characters where each character has two bytes, plus the word "Hello")
#include <iostream>
#include <string>
using namespace std;
int main()
{
wstring s = L"سلام hello";
wcout << s.substr(0,3) << endl;
wcout << s.substr(4,5) << endl;
return 0;
}
This should work: live on Coliru
#include <iostream>
#include <string>
#include <boost/regex/pending/unicode_iterator.hpp>
using namespace std;
template <typename C>
std::string to_utf8(C const& in)
{
std::string result;
auto out = std::back_inserter(result);
auto utf8out = boost::utf8_output_iterator<decltype(out)>(out);
std::copy(begin(in), end(in), utf8out);
return result;
}
int main()
{
wstring s = L"سلام hello";
auto first = s.substr(0,3);
auto second = s.substr(4,5);
cout << to_utf8(first) << endl;
cout << to_utf8(second) << endl;
}
Prints
سلا
hell
Frankly though, I think your substring calls are making weird assumptions. Let me suggest a fix for that in a minute: