From: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
Newsgroups: comp.os.msdos.djgpp
Subject: Re: Help with strings MID$?
Date: 29 Aug 1997 08:31:35 GMT
Organization: The National Capital FreeNet
Lines: 46
Message-ID: <5u61d7$97d@freenet-news.carleton.ca>
References: <01bcb3ea$4e6e4560$6889d2cd AT inventor DOT worldchat DOT com>
Reply-To: ao950 AT FreeNet DOT Carleton DOT CA (Paul Derbyshire)
NNTP-Posting-Host: freenet2.carleton.ca
To: djgpp AT delorie DOT com
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"Vincent Collura" (inventor AT worldchat DOT com) writes:
> Hello,
> 
> I am new to C++ and am trying to convert a 
> old QuickBasic utiltiy I wrote into C++.  It
> compiles fine except I still cant figure how
> to convert this Basic statement 
> 
> tally(item) = MID$(touch$, 2, 5) + MID$(touch$, 41, 12) + MID$(touch$, 73,
> 7)
> 
> Into c++,  For those who dont know, mid$ returns the 
> n'th character to the nth number.
> 
> What is the C++ function to do this?  I have 
> tried StrnCat but the problem with this is you
> cant specificy a starting location. 

Easy. You can, using pointers (which basic lacks, or hides very well anyways.)

char touch[256];   // touch$ (a string in C/C++ is an array of chars)
char tally[NUM_ITEMS][256];       // tally, an array of these arrays
char *temp;                       // Pointer

temp=touch+1;       // touch is also a pointer to the first character of
                    // touch$. temp is one past that: the second character.
tally[item][0]=0;   // Strings have a 0 char at the end as delimiter; this
                    // makes the first char of the string tally[item] null,
                    // making it an empty string.
strncat(tally[item],temp,5);
// The above 2 lines could be replaced with strncpy(tally[item],temp,5);
temp=touch+40;      // 41st character of touch$
strncat(tally[item],temp,12);
temp=touch+73;
strncat(tally[item],temp,7);


Note that this is more a C/C++ than DJGPP-specific issue, and might be
better placed in comp.lang.c or comp.lang.c++.
(The above works in C or C++.)
--
    .*.  Where feelings are concerned, answers are rarely simple [GeneDeWeese]
 -()  <  When I go to the theater, I always go straight to the "bag and mix"
    `*'  bulk candy section...because variety is the spice of life... [me]
Paul Derbyshire ao950 AT freenet DOT carleton DOT ca, http://chat.carleton.ca/~pderbysh