I'm learning C at the moment and I run into some problem, hard to understand what is going on with variables and adding text to variable in C.
I know C is not treating the strings and character as in other programming language. If I understand it correctly from my book: I have to define a variable before I can use it, that's ok for me. So, If I do this code, where I wish to print the variable text_1 it is failing:
#include <stdio.h>
int main()
{
char text_1[];
text_1[] = "Testing";
printf("Test 1 is: %s", text_1);
return(0);
}
But if I do this way, this is working:
#include <stdio.h>
int main()
{
char text_1[] = "Testing";
printf("Test 1 is: %s", text_1);
return(0);
}
In some other programming language I can do this way: Dim a as string
a="Testing"
print("Testing 1 is:", a) --> or similar option to print out the variable 'a'.
What is the correct way to do this in C?
Thank you.
Oops... C language is a rather low level language if you compare it to Java, Python or Ruby, or even Basic or JavaScript:
Long story made short, an array has a size that is defined only once (at definition time) and will never change during the life time of the array. char text_1[] = "Testing"; is an idiomatic initialization: the size of the array is set to the number of characters of the literal string + 1 for the terminating null, so here 8. After that text_1 will be able to contain other strings of at most 7 characters + 1 terminating null if you copy the relevant character for example with strcpy.
To go back to your code, char text_1[]; declares an incomplete array with a declared size of 0 bytes. That means that you cannot use it. The 2 correct ways would be:
char text_1[] = "Testing"; // idiomatic initialization of a 8 characters array
or
char text_1[8]; // definition of an uninitialized char array of size 8
strcpy(text_1, "Testing"); // copy a string into the array
Not really sexy, but C language is like that...
Ok, for conclusion, what is the correct way to learn how to set up a variable with string in a way I can print it to the screen or use it for compare with other variables who are also holding strings?
I like this way but I'm not sure is it correct to use:
char * text_1; // btw. what is this `*` meaning here?
text_1 = "Some text...";
printf("Variable text is: %s\n",text_1);
but this way is also acceptable by me:
char text_1[n]; // where n is a number of max char
strcpy(text_1, "Some text...");
printf("Variable text is: %s\n",text_1);