pointers - what is Fixed address variable in C -


i have seen many examples of in books , embedded system related sites.. per understanding , accessing data stored in fixed memory address . here example got in book; 

unsigned char *p=(unsigned char *)0x41e;

what use of type cast (unsigned char *) , there have used directly 

unsigned char *p=0x41e;

please explain in detail, what's use of type cast there, , storing address 0x41e pointer p or else stored in that?

i totally confused. please help.

what use of type cast.. (unsigned char *) , there have used directly unsigned char *p=0x41e

0x41e hexadecimal number , doesn't mean of type unsigned char *. should have tell compiler, casting unsigned char *, address (of type unsigned char *).

are storing address "0x41e" pointer p, or else stored in that.

yes, storing address 0x41e pointer p. doing unsigned char *p = (unsigned char *)0x41e, informing compiler p pointing memory location 0x41e , dereferencing p content stored @ memory location 0x41e.
check out running code: 

#include <stdio.h> int main() {     unsigned char *p=(unsigned char *)0x41e;     printf("%p\n",p); }

output:

0000041e  //output not 0x41e because '0x' used prefix inform compiler hexadecimal number

Comments

Post a Comment

Popular posts from this blog

php - Add the correct number of days for each month -

using following function can display years , months between 2 dates, how can add correct days each month array within each month? can't add days manually need account leap years etc. function yearmonth($start_date, $end_date) { $begin = new datetime( $start_date ); $end = new datetime( $end_date); $interval = new dateinterval('p1m'); // 1 month interval $period = new dateperiod($begin, $interval, $end); foreach ( $period $dt ) $years[$dt->format( "y" )][] = $dt->format( "f" ); return $years; } $list = yearmonth("2007-03-24", "2009-06-26"); var_dump($list); since nobody else answered: function yearmonth($start_date, $end_date) { $begin = new datetime( $start_date ); $end = new datetime( $end_date); $interval = new dateinterval('p1d'); // 1 month interval $period = new dateperiod($begin, $interval, $end); $lastmonth = null; $lastyear = null; $aresult = array(); forea...
Read more

java.util.scanner - How to read and add only numbers to array from a text file -

i'm learning java , have question regarding reading file want read numbers file contains strings well. here example of file: 66.56 "3 java 3-43 5-42 2.1 1 and here coding: public class test { public static void main (string [] args){ if (0 < args.length) { file x = new file(args[0]); try{ scanner in = new scanner( new fileinputstream(x)); arraylist<double> test = new arraylist<>(); while(in.hasnext()){ if(in.hasnextdouble()){ double f=in.nextdouble(); test.add(f);} else {in.next();} } catch(ioexception e) { system.err.println("exception during reading: " + e); } } my problem add 66.56,2.1 , 1 doesn't add 3 after "3 or ignores 3-43 , 5-42 can tell me how skip strings , add doubles here? thanks all said 3 ie; "3, 3-43 , 4-42 strings either u read string , split , check number @ " , - or put in space between characters , integers. jvm after compilation tre...
Read more