String assignement

String assignement

[HIToC]

Hello all!

I have a string CMD_LN that may contain a substring within angle brackets.
I would like to assign another string IN_BRACKETS with the substring that is
contained within the angle brackets of CMD_LN if it is present.

I have written this code that should work:


// A_brack.cpp

#include <iostream>
#include <string>

int main(int argc, char* argv[])
{
	string			cmd_ln, in_brackets;
	string::size_type	bg, ed;

	cmd_ln = "Hello <all>, hello world!\n";

	bg = cmd_ln.find('<');
	ed = cmd_ln.find('>', bg);
	if(bg != ed != string::npos) in_brackets.assign(cmd_ln, bg, ed);

	cout	<<"Starting string:\t" <<cmd_ln <<'\n'
		<<"Angle-brackets string:\t" <<in_brackets <<'\n'
		<<"bg:\t" <<bg <<"\ned:\t" <<ed <<'\n'
		<<cmd_ln[bg] <<' ' <<cmd_ln[ed] <<'\n';

	return	0;
}


The output should be:
Starting string:	Hello <all>, hello world!

Angle-brackets string:	<all>
bg:	6
ed:	10
< >


But...it is not; this is the output of the program:

Starting string:	Hello <all>, hello world!

Angle-brackets string:	<all>, hel
bg:	6
ed:	10
< >





Thanks!

-- 
With regards,


					HIToC
					hitoc_mail@yahoo.it

Re: String assignement

[Ron Michael Khu]

Hi!

I dont know much about c++ but after playing around with ur code,
i discovered that u gave the assign() method a wrong value for the 
second parameter...
why dont u try   "ed-bg+1" ??
(remove the '-1' if u like)

i think the second parameter is count or len... not the end index

-Ron

HIToC wrote:

>Hello all!
>
>I have a string CMD_LN that may contain a substring within angle brackets.
>I would like to assign another string IN_BRACKETS with the substring that is
>contained within the angle brackets of CMD_LN if it is present.
>
>I have written this code that should work:
>
>
>// A_brack.cpp
>
>#include <iostream>
>#include <string>
>
>int main(int argc, char* argv[])
>{
>	string			cmd_ln, in_brackets;
>	string::size_type	bg, ed;
>
>	cmd_ln = "Hello <all>, hello world!\n";
>
>	bg = cmd_ln.find('<');
>	ed = cmd_ln.find('>', bg);
>	if(bg != ed != string::npos) in_brackets.assign(cmd_ln, bg, ed);
>
>	cout	<<"Starting string:\t" <<cmd_ln <<'\n'
>		<<"Angle-brackets string:\t" <<in_brackets <<'\n'
>		<<"bg:\t" <<bg <<"\ned:\t" <<ed <<'\n'
>		<<cmd_ln[bg] <<' ' <<cmd_ln[ed] <<'\n';
>
>	return	0;
>}
>
>
>The output should be:
>Starting string:	Hello <all>, hello world!
>
>Angle-brackets string:	<all>
>bg:	6
>ed:	10
>< >
>
>
>But...it is not; this is the output of the program:
>
>Starting string:	Hello <all>, hello world!
>
>Angle-brackets string:	<all>, hel
>bg:	6
>ed:	10
>< >
>
>
>
>
>
>Thanks!
>
>  
>