I am going to store string arrays in an array in C.
For example
{
{"hello", "world"},
{"my", "name", "is"},
{"i'm", "beginner", "point", "makes"}
}
I'd like to store above data.
I tried to use
char *arr1 = {"hello", "world"};
char *arr2 = {"my", "name", "is"};
char *arr3 = {"i'm", "beginner", "point", "makes"}
But I don't know how to store those arrays in one array.
Thanks in advance.
ps.
How to print all element with?
const char **arr[] = {arr1, arr2, arr3};
If you want a char** array, just do :
const char *arr1[] = {"hello", "world", NULL};
const char *arr2[] = {"my", "name", "is", NULL};
const char *arr3[] = {"i'm", "beginner", "point", "makes", NULL};
const char **arr[] = {arr1, arr2, arr3, NULL};
Note that the NULL terminators are here to keep track of the different arrays' sizes, just like in a NULL-terminated string.
int i, j;
for(i = 0; arr[i] != NULL; ++i) {
for(j = 0; arr[i][j] != NULL; ++j) {
printf("%s ", arr[i][j]);
}
printf("\n");
}
Which would outputs :
hello world
my name is
i'm beginner point makes
arr[0], arr[1], arr[2]? One simple semi-conventional way would be to have a null pointer at the end of each sub-array: char *arr1[] = { "hello", "world", 0 };
NULL terminated array seems to be simpler than keeping array sizes.arr[] ? arr is an array of char**, arr[0], arr[1] and arr[2] are arrays of char*, arr[i][j] are actual strings (char*). Since arr[0] is an array of char*, you would have to do char** temp = arr[0].arr in one go without the arr1 sub-variables: const char **arr[] = { (const char *[]){ "hello", "world", NULL }, (const char *[]){ "my", "name", "is", NULL }, (const char *[]){ "i'm", "beginner", "point", "makes", NULL }, NULL, }; (which looks better when formatted on multiple lines).Unlike my initial assessment, it can be done with a single literal.
#include <stdio.h>
int main()
{
char* arr[3][4] = {
{"hello", "world"},
{"my", "name", "is"},
{"i'm", "beginner", "point", "makes"}
};
printf ("%s", arr[2][3]);
return 0;
}
Arrays 1 and 2 will be padded by zeroes at the end to be of length 4.
output:
makes
Tested it here: http://ideone.com/yDbUuz
char** pointers than actually needed, and you don't initialize them. Is this C-standard compliant or compiler tolerated ?
