Un esempio grafico delle operazioni di assegnamento di un puntatore la navigazione all’interno di array; essi vanno sotto il nome di aritmetica dei puntatori. Chiedete ad un programmatore C della vecchia guardia come ottimizzare un programma, e la prima cosa che vi dirà sarà di usare l’aritmetica sui puntatori. Capitolo 7 I puntatori in C Introduzione Dichiarazione e inizializzazione dei b[ 3 ] si può accedere effettuando un’operazione aritmetica sull’operatore *(b + 3.

Author: Zucage Shakabei
Country: Mexico
Language: English (Spanish)
Genre: Environment
Published (Last): 1 September 2011
Pages: 311
PDF File Size: 19.73 Mb
ePub File Size: 8.42 Mb
ISBN: 592-7-78968-639-6
Downloads: 27149
Price: Free* [*Free Regsitration Required]
Uploader: Tojashakar

Instead, describe the problem and what has been done so far to solve it. Once you understand pointers, pointer arithmetic is easy. To begin with, it may not work.

Da Wikipedia, l’enciclopedia libera. Puoi migliorare questa voce aggiungendo citazioni da fonti attendibili secondo le linee guida sull’uso delle fonti. I generally find it difficult to follow aeitmetica tutorials but this binky one was super simple, awesome and funny: Vediamo un caso concreto: For example, suppose we have an int array called arr. Gob00st 3, 5 33 The article linked to is great, makes sooo much more sense now! Visite Leggi Modifica Modifica wikitesto Cronologia.

The original value of number is The new value of number is 12 Before main calls cubebyvalue: Disagree with the ‘next’.

Start display at page:. Very concise and well put.

They’re modelled to behave very much as pointers, and to provide specializations that patch up raw pointers to work as proper iterators. Menu di navigazione Strumenti personali Accesso non effettuato discussioni contributi registrati entra. Aritmetcia using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.



But a Cei address can’t be added yo another one. A more elaborate explanation of this is given herefor example. Initialize the suit array Initialize the face array Initialize the deck array Shuffle the deck Deal 2 cards Clubs King The numbers go into the array Representing the order in which the cards are dealt Simulazione di mescolatore e distributore di carte Second refinement Convert shuffle the deck to For each of the 2 cards Place card number in randomly selected unoccupied slot of deck Convert deal 2 cards to For each of the 2 cards Find card number in deck array and print face and suit dri card Simulazione di mescolatore e distributore di carte Third refinement Convert shuffle the deck to Choose slot of deck randomly While chosen slot of deck has been previously airtmetica Choose slot of deck randomly Place card number in chosen slot of deck Convert deal 2 cards to For each slot of the deck array If slot contains card number Print the face and suit of the card.

This is one pretty good at link here about Pointer Arithmetic. So a more correct way of thinking of it is that pointers are simply iterators allowing you to iterate over allocated memory. Pointers have a few limitations that may not be strictly necessary on your CPU. Ountatori may aritmwtica a synonym for “int” for some compiler, but may be another type for another one.

C/C++ – Problemi di aritmetica dei puntatori –

To make this website work, we log user data and share it with processors. Ignaro di un secondo, piccolo particolare: You can subtract two pointers that point into the same buffer to get the number of elements between them, just like you can with iterators, and just like puntxtori iterators, if the pointers point into separate buffers, you can not meaningfully compare arutmetica.


We can also compute ptr – i. Ad esempio, molti programmatori preferiscono evitare la chiamata a funzioni di sistema come memcpy, creandosi dei loop locali per copiare zone di memoria.

Further, you’re not allowed to increment the null pointer, or more generally, a pointer must always point to allocated memory or one element pastor the arjtmetica null pointer constant 0. Sorry to be the 13th upvote! You might have a 32 bit platform where the compiler sees ints as 16 or 64 bit wide. Johannes Schaub – litb k 99 Di conseguenza, va trattato come un caso di copy-on-write. So subtracting pb from pa will yield 1, since they have one die distance.

TobySpeight “Usual” is irrelevant. Next address depends on the data type, more specifically on the size of the data type. For example never assume a pointer is the same size as a integer. I intended the 4 byte thing to just be an example, but I should probably have made that clearer, because pointers are certainly no guaranteed to be 4 bytes, and they often aren’t.

The only difference between it and regular arithmetic is that the number you are adding to the pointer will be multiplied by the size of the type that the pointer is pointing to.