Strings, Strings and Damned Strings

[Ben]

I have an int variable (always <100) that I want to convert to a two character string, e.g.

if myint = 1, mystr = "01"
if myint = 81, mystr = "81"

At the moment I can't figure out how to do this cleanly.
Then I wish to push a bunch of these strings into an array, for example:

typedef char LABEL[3];
LABEL mystrArray[100];

But having read a couple of tutorials I am still no clearer on the best way to do an "array of strings" in this situation, nor
how to do it.

Any help much appreciated!

cheers,

Ben

[doug turnbull]

Ben wrote:

I have an int variable (always <100) that I want to convert to a two character string, e.g.

if myint = 1, mystr = "01"
if myint = 81, mystr = "81"

At the moment I can't figure out how to do this cleanly.
Then I wish to push a bunch of these strings into an array, for example:

typedef char LABEL[3];
LABEL mystrArray[100];

But having read a couple of tutorials I am still no clearer on the best way to do an "array of strings" in this situation, nor
how to do it.

Any help much appreciated!

cheers,

Ben

For the first problem, google sprintf and pay attention to the
formatting specifiers. There's something in there to specify the width
of the string to be output, and whether or not to pad that width with
'0's or spaces.

Your second question, just do
char mystrArray[3][100];

Anything that requires an char* argument where you want to operate on
one of the elements of mystrArray (ie sprintf:
sprintf(mystrAr ray[0], <extra args> )
sprintf(mystrAr ray[1], <extra args> )
sprintf(mystrAr ray[2], <extra args> )

[santosh]

Ben wrote:

I have an int variable (always <100) that I want to convert to a two character string, e.g.

if myint = 1, mystr = "01"
if myint = 81, mystr = "81"

At the moment I can't figure out how to do this cleanly.
The simplest way would be to use sprintf(). However, you can also do
the conversion by indexing into a lookup table, each index being a
string literal representation of itself. For larger values of myint,
you can isolate the value of each digit, and then use a lookup table.
Then I wish to push a bunch of these strings into an array, for example:

typedef char LABEL[3];
LABEL mystrArray[100];

But having read a couple of tutorials I am still no clearer on the best way to do an "array of strings" in this situation, nor how to do it.

Use an array, (either static or dynamic), of pointers to char and store
the strings by malloc'ing each member of the array to the required
size. If you know the sizes of strings in advance and if they won't
change during execution, then a static 2d array might be simpler.

[Dann Corbit]

"Ben" <be*********@sp am.me> wrote in message
news:12******** *****@corp.supe rnews.com...

I have an int variable (always <100) that I want to convert to a two
character string, e.g.

if myint = 1, mystr = "01"
if myint = 81, mystr = "81"

At the moment I can't figure out how to do this cleanly.
sprintf()
Probably you want "%02d" for your format specifier.
Then I wish to push a bunch of these strings into an array, for example:

typedef char LABEL[3];
LABEL mystrArray[100];
That looks fine. Except I would not have a screaming typedef. It looks too
much like a macro.
But having read a couple of tutorials I am still no clearer on the best
way to do an "array of strings" in this situation, nor how to do it.

Any help much appreciated!
Show us your program that demonstrates what you have tried, and what went
wrong.
cheers,

Ben

[Dann Corbit]

"Dann Corbit" <dc*****@connx. com> wrote in message
news:e7******** **@nntp.aioe.or g...

Maybe something like this:

#include <stdio.h>
#include <string.h>

typedef char Label[3];

int main(void)
{
size_t i;
Label mystrArray[100]={0};

for (i = 0; i < 100; i++)
sprintf(mystrAr ray[i], "%02d", i);

for (i = 0; i < 100; i++)
puts(mystrArray[i]);

return 0;
}

[Ben]

Dann Corbit wrote:

"Dann Corbit" <dc*****@connx. com> wrote in message
news:e7******** **@nntp.aioe.or g...

Maybe something like this:

#include <stdio.h>
#include <string.h>

typedef char Label[3];

int main(void)
{
size_t i;
Label mystrArray[100]={0};

for (i = 0; i < 100; i++)
sprintf(mystrAr ray[i], "%02d", i);

for (i = 0; i < 100; i++)
puts(mystrArray[i]);

return 0;
}

sprintf solves the first problem, but the array is still confusing me...here's the actual code:
char *labelArray [(4*MAX2*MAX2)+1];

int mkLabels(void) {

char blkid[3],colid[3],rowid[3],digit[3];
int i,j,colnum,rown um;
pCELL pointer = mArray[0][0][0][0];

for (i=0;i<n4;i++) {

printf("Making column labels for square %d\n",i);

char alabel[6] = "a";
char blabel[6] = "b";
char clabel[6] = "c";
char dlabel[6] = "d";

sprintf(blkid, "%02d",poin ter->block);

int sindex = ilookup(pointer->symbol); /*printf("sindex is %d\n",sindex);*/
sprintf(digit, "%02d",sind ex);

/* For columns and rows we have to do some annoying mapping to a two-digit identifier - mArray's fault */
colnum = (pointer->column)+((poin ter->block%n)*n);
sprintf(colid, "%02d",coln um);

rownum = (pointer->row)+((point er->block/n)*n);
sprintf(rowid, "%02d",rown um);
printf("blkid is %s, colid is %s, rowid is %s, digit is %s\n",blkid,col id,rowid,digit) ;

strcat(alabel,r owid); strcat(alabel,c olid);
labelArray[i] = alabel;

strcat(blabel,d igit); strcat(blabel,r owid);
labelArray[i+n4] = blabel;

strcat(clabel,d igit); strcat(clabel,c olid);
labelArray[i+n4+n4] = clabel;

strcat(dlabel,d igit); strcat(dlabel,b lkid);
labelArray[i+n4+n4+n4] = dlabel;

1) printf("alabel is %s, blabel is %s, clabel is %s, dlabel is %s\n",alabel,bl abel,clabel,dla bel);

pointer = pointer->next_in_puzzle ;
}

2) printf("\nConte nts of labelArray:\n") ;
for (j=0;j<4*n4;j++ ) {
printf("%s ",labelArra y[j]);
}
printf("\n\n");

return 0;

}

This compiles and runs ok but doesn't work as required since each update to alabel, blabel etc changes those objects that all
the pointers point to, so I am not storing new labels just overwriting the same ones (the print contents at 2) confirms that).
Note I want the whole structure labelArray to be available globally which is another problem with the code above.

So I need to do something differently, perhaps the 2d array, but I couldn't get that to compile. At least the values at 1) are
correct, just the structure is wrong.

[Bill Pursell]

Ben wrote:

char *labelArray [(4*MAX2*MAX2)+1];
<snip>
This compiles and runs ok...

No, it doesn't. The very first lines references MAX2,
which isn't defined.

[Ben]

Bill Pursell wrote:

Ben wrote:

char *labelArray [(4*MAX2*MAX2)+1];

<snip>

This compiles and runs ok...

No, it doesn't. The very first lines references MAX2,
which isn't defined.

It didn't have a main() or include any headers either, but most people should have no problem working out the value of MAX2 is
irrelevant to the problem.

[Kenny McCormack]

In article <12************ *@corp.supernew s.com>,
Ben <be*********@sp am.me> wrote:

Bill Pursell wrote:

Ben wrote:

char *labelArray [(4*MAX2*MAX2)+1];

<snip>

This compiles and runs ok...

No, it doesn't. The very first lines references MAX2,
which isn't defined.

It didn't have a main() or include any headers either, but most people
should have no problem working out the value of MAX2 is
irrelevant to the problem.

Yes, but that's not how this newsgroup works.

http://en.wikipedia.org/wiki/Aspergers

[Ben Pfaff]

Ben <be*********@sp am.me> writes:

I have an int variable (always <100) that I want to convert to a two character string, e.g.

if myint = 1, mystr = "01"
if myint = 81, mystr = "81"

At the moment I can't figure out how to do this cleanly.

You've already received a number of suggestions to use
sprintf(). This is one good way.

For a problem as simple as this, though, you can easily do it by
hand, if you like:
mystr[0] = myint / 10 + '0';
mystr[1] = myint % 10 + '0';
--
Go not to Usenet for counsel, for they will say both no and yes.