how to check a string whether it is

[zjffdu]

I know in .net it is easy, but in C++
how can I check a string whether it is composed by backspace,\t,\n?
Is there function can i call in the standard?

thanks for any hint

 

[Jim Langston]

I know in .net it is easy, but in C++
how can I check a string whether it is composed by backspace,\t,\n?
Is there function can i call in the standard?

thanks for any hint

Not exactly sure what you're asking for. But std::string.find_first_of()
might be what you want. "Whether it is composed by..." Is it totally? Or
included? Totally would be a simple == as in if ( MyString == "\t" ) has
within you could use if ( MyString.find_first_of("\t") != std::npos );

 

[zjffdu]

thanks
I mean how to judge a string whether there is no any other character
besides backspace,\t,and \n

 

[Dietmar Kuehl]

I mean how to judge a string whether there is no any other character
besides backspace,\t,and \n

if (str.find_first_not_of("\t\n\b") == str.npos)
std::cout << "the string contains nothing interesting\n";

 

[Diego Martins]

http://www.cppreference.com/cppstring/index.html

 

[Tomás]

zjffdu posted:

I know in .net it is easy, but in C++
how can I check a string whether it is composed by backspace,\t,\n?
Is there function can i call in the standard?

thanks for any hint

Here's an elementary way to test if either character is present:

bool EitherPresent( const char* p )
{
for( ; ; ++p )
{
switch ( *p )
{
case '\t':
case '\n':
{
return true;
}

case 0:
{
return false;
}
}
}
}


-Tomás

 

[Tomás]

zjffdu posted:

thanks
I mean how to judge a string whether there is no any other character
besides backspace,\t,and \n

Simple again.

bool AnythingIntelligible( const char* p )
{
for( ; ; ++p )
{
switch ( *p )
{
case '\t':
case '\n':

break;

case 0:
{
return false;
}

default:

return true;
}
}
}

 

[Dietmar Kuehl]

http://www.cppreference.com/cppstring/index.html

Er, I think I know the standard C++ library quite well. Did I goof?
.... and, if so, where?

 

[Ben Pope]

http://www.cppreference.com/cppstring/index.html

Do you have a point?

I'm pretty sure you're not just randomly pasting links into messages but
it would be good to quote some context from the post to which you are
responding, and also adding some words to describe the point of
providing the link.

Ben Pope

 

[=?ISO-8859-15?Q?Juli=E1n?= Albo]

if (str.find_first_not_of("\t\n\b") == str.npos)
std::cout << "the string contains nothing interesting\n";

If the string contains a program in the whitespace language, it can be very
interesting.