hi
or is there a better way to check the existence of "py" in a string
"s"?
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
thanks
5  3261 
Gary Wessle wrote:
or is there a better way to check the existence of "py" in a string
"s"?
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
'find' returns 'std::string::npos' if the [sub]string is NOT found. So,
if you just wanted to check the existence, you just need to check the
return value of 'find'. There is no need to extract and compare. RTFM
V
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"Victor Bazarov" <v.********@comAcast.netwrites:
Gary Wessle wrote:
>or is there a better way to check the existence of "py" in a string
"s"?
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
'find' returns 'std::string::npos' if the [sub]string is NOT found. So,
if you just wanted to check the existence, you just need to check the
return value of 'find'. There is no need to extract and compare. RTFM
V
--
Please remove capital 'A's when replying by e-mail
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the fix:
string s = "djrfpyfd";
string t = "pyd";
if ( (s.find(t,0))!= string::npos )
cout << "found" << endl;
however the next does not work
#include <string>
using std::string;
( (s.find(t,0))!= string::npos ) ? return 2.0 : return 4.0;
I get
: error: expected primary-expression before 'return'
: error: expected `:' before 'return'
: error: expected primary-expression before 'return'
: error: expected `;' before 'return'
: error: expected primary-expression before ':' token
: error: expected `;' before ':' token
Gary Wessle wrote:
"Victor Bazarov" <v.********@comAcast.netwrites:
>Gary Wessle wrote:
>>or is there a better way to check the existence of "py" in a string
"s"?
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
'find' returns 'std::string::npos' if the [sub]string is NOT found.
So, if you just wanted to check the existence, you just need to
check the return value of 'find'. There is no need to extract and
compare. RTFM
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
the fix:
string s = "djrfpyfd";
string t = "pyd";
if ( (s.find(t,0))!= string::npos )
cout << "found" << endl;
however the next does not work
#include <string>
using std::string;
( (s.find(t,0))!= string::npos ) ? return 2.0 : return 4.0;
I get
>error: expected primary-expression before 'return'
error: expected `:' before 'return'
error: expected primary-expression before 'return'
error: expected `;' before 'return'
error: expected primary-expression before ':' token
error: expected `;' before ':' token
Well, you're trying to have a statement inside an expression.
You simply cannot do that.. What you probably want is
return s.find(t) != string::npos ? 2.0 : 4.0 ;
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
"Victor Bazarov" <v.********@comAcast.netwrites:
Gary Wessle wrote:
>"Victor Bazarov" <v.********@comAcast.netwrites:
>>Gary Wessle wrote:
or is there a better way to check the existence of "py" in a string
"s"?
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
'find' returns 'std::string::npos' if the [sub]string is NOT found.
So, if you just wanted to check the existence, you just need to
check the return value of 'find'. There is no need to extract and
compare. RTFM
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
the fix:
string s = "djrfpyfd";
string t = "pyd";
if ( (s.find(t,0))!= string::npos )
cout << "found" << endl;
however the next does not work
#include <string>
using std::string;
( (s.find(t,0))!= string::npos ) ? return 2.0 : return 4.0;
I get
>>error: expected primary-expression before 'return'
error: expected `:' before 'return'
error: expected primary-expression before 'return'
error: expected `;' before 'return'
error: expected primary-expression before ':' token
error: expected `;' before ':' token
Well, you're trying to have a statement inside an expression.
You simply cannot do that.. What you probably want is
return s.find(t) != string::npos ? 2.0 : 4.0 ;
that returns -5.20371e-39
it is only when I do
double y;
(s.find(t,0))!= string::npos ? y=2.0 : y=4.0;
return y;
that it works
Gary Wessle wrote:
"Victor Bazarov" <v.********@comAcast.netwrites:
>Gary Wessle wrote:
>>"Victor Bazarov" <v.********@comAcast.netwrites:
Gary Wessle wrote:
or is there a better way to check the existence of "py" in a
string "s"?
>
string s = "djrfpyfd";
string t = "py";
string r = s.substr(s.find("py"),2);
cout << (t==r) << endl;
'find' returns 'std::string::npos' if the [sub]string is NOT found.
So, if you just wanted to check the existence, you just need to
check the return value of 'find'. There is no need to extract and
compare. RTFM
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask
the fix:
string s = "djrfpyfd";
string t = "pyd";
if ( (s.find(t,0))!= string::npos )
cout << "found" << endl;
however the next does not work
#include <string>
using std::string;
( (s.find(t,0))!= string::npos ) ? return 2.0 : return 4.0;
I get
error: expected primary-expression before 'return'
error: expected `:' before 'return'
error: expected primary-expression before 'return'
error: expected `;' before 'return'
error: expected primary-expression before ':' token
error: expected `;' before ':' token
Well, you're trying to have a statement inside an expression.
You simply cannot do that.. What you probably want is
return s.find(t) != string::npos ? 2.0 : 4.0 ;
that returns -5.20371e-39
Really?!
it is only when I do
double y;
(s.find(t,0))!= string::npos ? y=2.0 : y=4.0;
return y;
that it works
I think that's covered in the FAQ 5.8.
V
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