compiler errors - undefined reference to `roundf' - C language -

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i'm new c , keep running same error. typing code in nano text editor , compiling in linux terminal. operating system ubuntu 14.04. here's example of code won't compile,

    #include <math.h>     #include <stdio.h>     int main()     {         float x = 23.33f;         x = roundf(x);         printf("%f\n", x);         return (0);     }

the error receiving is,

    cc     example.c   -o example     /tmp/ccwv0or8.o: in function `main':     example.c:(.text+0x1d): undefined reference `roundf'     collect2: error: ld returned 1 exit status     make: *** [example] error 1

any appreciated, thanks!

link math library:

cc example.c -o example -lm

the math library functions not part of standard c library linked default. need link yourself.

there's interesting thread why it's not part of libc:

why have link math library in c?


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