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This page presents the sometimes confusing way in which C handles the passing of array structures.

In C, a string variable is actually an array of characters.

In C, an array is always passed by reference. This means that the parameter passed can be changed.

Technical point: Assume the following string declarations.
char s1[256]; char s2[256]; char s3[256];
In C, a string is actually an array of characters.

Then, in C, the following produce the same result.
scanf("%s",&s1); scanf("%s",s2); scanf("%s",&s3[0]);
Note: The address of the array s1 and the address of the array element s1[0] are the same address.

Note: A scanf for a string using "%s[^\n]" will cause an error if there is not "\n" (newline) at the end of the file. Here, just text until a space or end of file is input. Previously, the address-of operator, ampersand "&", was used for all variables to scanf to have a consistent notation.

In passing parameters in general, we will usually stop using the ampersand "&" for arrays in general and strings as arrays of characters in particular.

The output is in the usual manner.
printf("%s\n",s1); printf("%s\n",s2); printf("%s\n",s3);

Here is a program to illustrate this.

Here is the C code.
#include <stdio.h> int main() { char s1[256]; char s2[256]; char s3[256]; scanf("%s",&s1); scanf("%s",s2); scanf("%s",&s3[0]); printf("%s\n",s1); printf("%s\n",s2); printf("%s\n",s3); return 0; }

Here are some examples of input and output for the above program code.

Here is an example input.
one two three
For the above example input, here is the expected output.
one two three