Strings

• Sequence of characters enclosed in double quotes

• A one-dimensional character array can be used to store a string (as long as it ends with a null character \0)

Declaration

1. Vector declaration of a char vector with length length

char string_name[length];

1. Dynamic allocation dynamic allocation of a memory area of length bytes, which is organized as a char sequence (1 Byte each)

char *string_name;
string_name=malloc(length);

Inizialization

1. With implicit size

   char  string_name[] = "value";

   where the length of the string is:

   sizeof(string_name) - 1

2. With explicit size

   char  nomeStringa[lenght] = "value";

   • if length >= (num_string_characters + 1), the string occupies the "value" number of characters + 1 (/0)

   • else KILLED PROCESS

Vector of strings

1. With an array

   char  vector_name[array_size][string_size];

2. With a pointer

   char **vector_name =NULL;
   vector_name=malloc(array_size * sizeof(char*));
   
   int i;
   
   for (i = 0; i<array_size; i++)
        vector_name[i] = malloc(sizeof(char)*string_size);

Initialization

1. With an array

   char vector_name[array_size][string_size] = ["value1", "value2", ...];

   where:

   • array_size: number of strings in the vector (# of elements)

   • string_size: maximum number of characters for the strings

   One or both the parameters can be omitted and are retrieved automatically.

2. With a pointer

   char *vector_name[string_size] = ["value1", "value2", ...];

   It implicitly calculates both the number of strings and the number of characters in each individual string (by evaluating the values on the left)

   char  **p =NULL;
   p=malloc(3 * sizeof(char*));
   
   int i;
   for (i = 0; i<3; i++)
        p[i] = malloc(sizeof(char)*3);