Thread: Create strings based on input int?

I am a beginner in C, and I was trying to make a program which reads an "int x" and creates a number of strings equivalent to the "x", and also name the variables accordingly in series such as:string1,string2,... . I tried many ways to do it by myself and I also looked for it in many tutorials but I couldn't figure it out. So please help me if you can Please also tell me if I haven't done my homework and where I should look because I did look for it and search for it but with no luck so far.

For example I was trying to create a program to calculate the GPA of a student, so first I asked about the no. of subjects he was taking "x", then I wanted the program to create a no. of strings that are named in series:sub1,sub2,sub3,... that equal the no. of subjects and then I would ask the student to enter their names one by one. Can this be done using arrays?? If so how can I make the index no. of the array element per subject a variable that is increased automatically??
Thanks for your help

If I understand correctly, you just want an array of strings:
[sub1,sub2,sub3]
You'd essentially have a dynamic 2-d array like this:

int numSubjects=10; // read this in
char **subjects;

then you malloc it:
subjects = (char**)malloc(sizeof(char*)*numSubjects);

then you can assign values like an array:
subjects[0] = "why am I taking";
subjects[1] = "c programming?";
subjects[2] = "calculus";

before you quit you free it:
free (subjects);

Originally Posted by omaralqady

I am a beginner in C, and I was trying to make a program which reads an "int x" and creates a number of strings equivalent to the "x", and also name the variables accordingly in series such as:string1,string2,... . I tried many ways to do it by myself and I also looked for it in many tutorials but I couldn't figure it out. So please help me if you can Please also tell me if I haven't done my homework and where I should look because I did look for it and search for it but with no luck so far.

Well actually it is much simpler to avoid using arrays, by writting a progra mthat writes a program tailor made to the user needs :P.
However my solution assumes the user has configured his path to be able to invoke the c compiler and immediately enter the desired strings. Notice the care taken to properly indent the resulting program.

Code:

#include <stdio.h>
int main()
{
        int nsub, i;
        FILE *f;

        printf("Enter the number of subjects:");
        scanf("%d", &nsub);
                if( (f = fopen("prog.c","w")) == NULL)
        return printf("Error opening file.\n");
        fputs("#include <stdio.h>\n\nint main()\n{", f);
        fprintf(f, "\tint i;\n");
        for(i=0; i<nsub; i++)
                fprintf(f, "\tchar string%d[256];\n", i);
        fprintf(f, "\n");
        for(i=0; i<nsub; i++)
        {
                fprintf(f, "\tprintf(\"Please enter string%d:\");\n", i);
                fprintf(f, "\tfgets(string%d, 256, stdin);\n", i);
        }
        fprintf(f, "\n\treturn 0;\n}\n");
        fclose(f);
        system("gcc -o prog prog.c");
        system("./prog");

        return 0;
}

This is just a joke actually, and not to be taken seriously.