Save strings from for loop to an array in c

Question

I am trying to get substrings from a string (a=ATCG) and then store it in an array but I am getting a warning: assignment makes integer from pointer without a cast [enabled by default] dna[i]=dna1;

I want the output array to print: ATCG TCG CG G

I am new to C, how do I fix this?

Here's my program

int main()
{
    char a[]="ATCG", dna[20], *dna1  ;

    dna1 = (char *)malloc(2000);
    int i, len_of_seg_2;
    for(i = 0; i < strlen(a); i++)
    {
        len_of_seg_2=strlen(a)-i+1;  
        strncpy(dna1, a+i, len_of_seg_2); 
        dna1[len_of_seg_2-1]='\0';

        dna[i]=dna1;
        printf("sequence:%s\n",dna1);
    }
    for(i=0;i<5;i++){
        printf("\nseq:%s\n",dna[i]);
    }
    return 0;   
}

dna1 is char *, dna[i] is char. The error is exactly what it says. You are assigning a pointer to an integer value. Maybe you meant dna[i] = *dna1? Also, remember to free(dna1) for good practice. — ddz
– ddz, Commented Apr 29, 2016 at 2:39
What are you trying to do in the statement dna[i]=dna1;? Are you trying to copy a single character, or a string. If you are trying to copy a string, then why is the destination (dna[i]) a character? — Kyle A
– Kyle A, Commented Apr 29, 2016 at 2:44
I am trying to copy the entire string. In the statement dna [i]=dna1; I am trying to store dna1 as element number i in the dna array. Thanks — user2694962
– user2694962, Commented Apr 29, 2016 at 14:23

kfsone · Accepted Answer · 2016-04-29 03:00:16Z

2

You were missing a '*' infront of dna[20].

int main()
{
    char a[]="ATCG";
    char *dna[20];  // <-- this was char dna[20]
    char *dna1;

    dna1 = (char *)malloc(2000);
    int i, len_of_seg_2;
    for(i = 0; i < strlen(a); i++)
    {
        len_of_seg_2=strlen(a)-i+1;  
        strncpy(dna1, a+i, len_of_seg_2); 
        dna1[len_of_seg_2-1]='\0';

        dna[i]=dna1;  // <-- this was the crash
        printf("sequence:%s\n",dna1);
    }
    for(i=0;i<5;i++){
        printf("\nseq:%s\n",dna[i]);
    }
    return 0;   
}

Live demo: http://ideone.com/ZhO3SZ

answered Apr 29, 2016 at 3:00

kfsone

24.4k3 gold badges46 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

user2694962 Over a year ago

It prints from the first for loop. However I am trying to print it out from the second for loop so that I can access the stored subsequences elsewhere in the code. From the second for loop it only prints the last subsequence, G. Thanks for your comment.

ddz · Accepted Answer · 2016-04-29 02:51:10Z

0

the type of dna1 is char *, and the type of dna[i] is char. The error is exactly what it says. You are assigning a pointer (dna1) to an integer value (dna[i]). You can't do that - actually, you can and you did, which is why you saw this warning - without explictly telling the compiler that you want to do it (dna[i] = (char)dna1; in this case). Maybe you meant dna[i] = *dna1?. I don't know what you want to do.

Also, remember to free(dna1) for good practice.

answered Apr 29, 2016 at 2:51

ddz

5263 silver badges15 bronze badges

Collectives™ on Stack Overflow

Save strings from for loop to an array in c

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related