二维指针数组C

Question

This may be fairly easy to answer but i cant seem to figure out the syntax for it. What i need is a 2D array the first element would be pointers to CSTRING's and the second element would be a counter.

The purpose of this is for threading and passing word lists to threads based on the thread number. As in if it was defined something like char wordlists[100][10] (100 words and 10 lists 1 for each thread 10 total) i could initially fill all the lists up with words from a file and then pass a specific list to a thread to process and once a thread joins back to the main thread i would refill the word list related to the joining thread and relaunch the thread with new words.

Overall i dont get the syntax for making a 2D array of pointers (first element pointers second just a counter). Also is it possible to pass just the array address where the words for the particular thread starts at so i dont need to pass the entire 2D array of 1000 words? (so that i can just pass the starting address where that threads 100 words are stored)

thanks for the help!

edit:: if you guys have any better suggestions for a similar way to process big word files via threads then do suggest them im open to more ideas.

Answer 1

i dont get the syntax for making a 2D array of pointers

* has a lower precedence than [] . Therefore wordlists is an array of array of pointer to char .

char *wordlists[100][10];

Answer 2

To declare a 2D array of pointers (to type T ):

T *array[width][height];

Also is it possible to pass just the array address [...] so I don't need to pass the entire 2D array of 1000 words?

You couldn't even do anything else. In C, arrays are always passed by pointer, not by value.

Answer 3

You probably can benefit from reading the (relevant parts of, but i'd recommend the WHOLE of) the comp.lang.c FAQ .

It is probably a mandatory read for anyone touching C (and C-like langages), and it is incredibly eye-opening (especially about undefined statements behavior, null pointers value and use, and, in your case, pointers and arrays of pointers).