void main()
{
int a={1,2,3,4,5,6,7,8,9,10};
int *p=a;
int *q=&a;
cout<<q-p+1<<endl;
}
The output is 10, how?
if we give cout<<q it will print the address, value won't print....
if we give cout<<p it will print the address, value won't print....
p has the base addr; q... (1 Reply)
can u tell me the reson that why we should not delete a pointer twice.?
if we delete ponter twice then what happen and why this happen
Regards,
Amit (2 Replies)
If one wants to get a start address of a array or a string or a block of memory via a function, there are at least two methods to achieve it:
(1) one is to pass a pointer-to-pointer parameter, like:
int my_malloc(int size, char **pmem)
{
*pmem=(char *)malloc(size);
if(*pmem==NULL)... (11 Replies)
Hi,
Can anyone tell me how i can declare and allocate dynamically an array of pointers to structured type?? Is declaration something like this:?
struct_name ** array; (1 Reply)
Hi guys, I'm trying to understand pointers in C and made a simple example and I've problems with It.
Can someone help?
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
int f1(char **str_);
int main(int argc, char **argv)
{
char *str = NULL;
f1(&str);
... (3 Replies)
Does anyone know?
int x = 1;
int *p = &++x; //ok !
int *q = &x++; //gives an error :O
why the first pointer is ok but the second is an error? (13 Replies)
Here are two programs that pass a pointer to a variable but behave differently. Shouldnt the i in second program be 0 after the function call?
#include<stdio.h>
void changeI(int *i)
{
*i = 10;
}
int main(void)
{
int i=5;
printf("%d before\n", i);
changeI(&i);
printf("%d... (1 Reply)
how to copy content of character pointer to character array in c programming..
char *num;
char name=num; (1 Reply)
Discussion started by: zinat
1 Replies
LEARN ABOUT REDHAT
pdl::char
Char(3) User Contributed Perl Documentation Char(3)NAME
PDL::Char -- PDL subclass which allows reading and writing of fixed-length character strings as byte PDLs
SYNOPSIS
use PDL;
use PDL::Char;
my $pchar = PDL::Char->new( [['abc', 'def', 'ghi'],['jkl', 'mno', 'pqr']] );
$pchar->setstr(1,0,'foo');
print $pchar; # 'string' bound to "", perl stringify function
# Prints:
# [
# ['abc' 'foo' 'ghi']
# ['jkl' 'mno' 'pqr']
# ]
print $pchar->atstr(2,0);
# Prints:
# ghi
DESCRIPTION
This subclass of PDL allows one to manipulate PDLs of 'byte' type as if they were made of fixed length strings, not just numbers.
This type of behavior is useful when you want to work with charactar grids. The indexing is done on a string level and not a character
level for the 'setstr' and 'atstr' commands.
This module is in particular useful for writing NetCDF files that include character data using the PDL::NetCDF module.
FUNCTIONS
new
Function to create a byte PDL from a string, list of strings, list of list of strings, etc.
# create a new PDL::Char from a perl array of strings
$strpdl = PDL::Char->new( ['abc', 'def', 'ghij'] );
# Convert a PDL of type 'byte' to a PDL::Char
$strpdl1 = PDL::Char->new (sequence (byte, 4, 5)+99);
$pdlchar3d = PDL::Char->new([['abc','def','ghi'],['jkl', 'mno', 'pqr']]);
string
Function to print a character PDL (created by 'char') in a pretty format.
$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
# ['abc' 'def' 'ghi']
# ['jkl' 'mno' 'pqr']
# ]
# 'string' is overloaded to the "" operator, so:
# print $char;
# should have the same effect.
setstr
Function to set one string value in a character PDL. The input position is the position of the string, not a character in the string. The
first dimension is assumed to be the length of the string.
The input string will be null-padded if the string is shorter than the first dimension of the PDL. It will be truncated if it is longer.
$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
$char->setstr(0,1, 'foobar');
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
# ['abc' 'def' 'ghi']
# ['foo' 'mno' 'pqr']
# ]
$char->setstr(2,1, 'f');
print $char; # 'string' bound to "", perl stringify function
# Prints:
# [
# ['abc' 'def' 'ghi']
# ['foo' 'mno' 'f'] -> note that this 'f' is stored "f "
# ]
atstr
Function to fetch one string value from a PDL::Char type PDL, given a position within the PDL. The input position of the string, not a
character in the string. The length of the input string is the implied first dimension.
$char = PDL::Char->new( [['abc', 'def', 'ghi'], ['jkl', 'mno', 'pqr']] );
print $char->atstr(0,1);
# Prints:
# jkl
perl v5.8.0 2001-05-27 Char(3)