g++ 3.2.X: undefined reference to `abs(int)'

[Daniel Heiserer]

hi,

I am sure that is a stupid error of mine, but why the hell
does this not work:
-------------------------------------------

g++ test.cc

/tmp/ccUN1Hel.o: In function `main':
/tmp/ccUN1Hel.o(.text+0x26): undefined reference to `abs(int)'
collect2: ld returned 1 exit status
-------------------------------------------

cat test.cc

#include <stdlib.h>
#include <stdio.h>

int main(){
int abs(int);
for (int jj=10;jj>=-10;jj--){
fprintf(stdout,"%d ===> %d\n",jj,abs(jj));
}
return 0;
}
-------------------------------------------

man 3 abs

ABS(3) Linux Programmer's
Manual ABS(3)
NAME
abs, labs, llabs, imaxabs - compute the absolute value of an
integer.
SYNOPSIS
#include <stdlib.h>

int abs(int j);
long int labs(long int j);
long long int llabs(long long int j);

 

[Attila Feher]

hi,

I am sure that is a stupid error of mine, but why the hell
does this not work:
-------------------------------------------
/tmp/ccUN1Hel.o: In function `main':
/tmp/ccUN1Hel.o(.text+0x26): undefined reference to `abs(int)'
collect2: ld returned 1 exit status
-------------------------------------------
#include <stdlib.h>
#include <stdio.h>

int main(){
int abs(int);

You don't need the above line. <stdlib.h> declares abs so you must not do
it.

 

[Chris Dams]

Hello,

#include <stdlib.h>
#include <stdio.h>

Should nowadays be:

#include <cstdlib>
#include <cstdio>

using namespace std;

int main(){
int abs(int);

Remove this line, that will solve the error.

for (int jj=10;jj>=-10;jj--){
fprintf(stdout,"%d ===> %d\n",jj,abs(jj));
}
return 0;
}

Bye,
Chris Dams