Are they ever anything but a pointer? The only difference when it's local is, it knows it's a const one whose base can't be changed...
Yes, there's a difference. A reference in code to a non-subscripted array is evaluated as the address of the first element of the array. That's not quite the same as a pointer. A pointer can be an l-value, a "naked" array reference can't be.
Thus
is fine, but
should (offhand) result in a syntax error, even though both could be called like this:
Dear all,
How can i unset arrays. I mean all the subscripts including the array after using them.
Could you direct me to some links of array memory handling in the korn shell.
Thanks (2 Replies)
PHP question...
I have an SQL query that's pulled back user IDs as a set of columns. Rather than IDs, I want to use their names.
So I have an array of columns $col with values 1,7,3,12 etc and I've got an array $person with values "Fred", "Bert", "Tom" etc
So what I want to do is display the... (3 Replies)
Hello,
I am some what of a newbie to awk scripting and I seem to be struggling with this problem.
I know I need to use arrays but I can't figure out how to use them.
I have an input file that looks like this;
Name,Team,First Test, Second Test, Third Test
Crystal,Red,5,17,22... (1 Reply)
We have 2 servers (L1000 and rp7410) running 11.11. We would like to hook them up to either a Hitatchi AMS 2500 or Hitachi USPV via fiber channel. I need to what drivers I need for this and if it will work. Oh, they are using HP Tachyon XL2 Fiber Channel Mass Storage Adapters.
Thanks,
Bill (1 Reply)
hi everybody
can anyone help me with usage of 2 dimensional arrays in unix. please provide a suitable example for accessing individual elements as well as all elements.
Thanks (2 Replies)
I have three arrays. One is Master array and that has list of other array in config file.
for e.g (for simplicity I have only defined array with 2 elements each)
set +A MASTERARRAY SQLUPDATE_ONETIME SQLUPDATE_DAILY END_OF_ARRAY
set +A SQLUPDATE_ONETIME update12 update22 END_OF_ARRAY... (4 Replies)
if i declare both but don't input any variables what values will the int array and file pointer array have on default, and if i want to reset any of the elements of both arrays to default, should i just set it to 0 or NULL or what? (1 Reply)
Hi all,
I have a file test1.txt with the below contents
abc
def
ghj
xyz
I tried printing these values using arrays.
Script tried :
===========
set -A array1 `cat test1.txt`
count=${#array1
}
i=0
while
do
echo "element of array $array1"
done (1 Reply)
I have never used arrays before but I have a script like this:
var1=$(for i in $(cat /tmp/jobs.021013);do $LIST -job $i -all |
perl -ne 'print /.*(\bInfo.bptm\(pid=\d{3,5}).*/' | tr -d "(Info=regpid" | tr -d ')'; $LIST -job $i -all |
cut -f7 -d','| sed -e "s/^\(*\)\(*\)\(*\)\(.*\)/\1... (2 Replies)
Am using bash
For eg:
Suppose i have a array
arr=(1 2 3 4 5 6 7 8 9 10 11 12)
suppose i give input 5 to a script and script should able to print values greater than or equal to 5 like below:
Input:
5
output:
5,6,7,8,9,10,11,12 (7 Replies)
Discussion started by: manid
7 Replies
LEARN ABOUT PHP
unset
UNSET(3) 1 UNSET(3)unset - Unset a given variableSYNOPSIS
void unset (mixed $var, [mixed $...])
DESCRIPTION unset(3) destroys the specified variables.
The behavior of unset(3) inside of a function can vary depending on what type of variable you are attempting to destroy.
If a globalized variable is unset(3) inside of a function, only the local variable is destroyed. The variable in the calling environment
will retain the same value as before unset(3) was called.
<?php
function destroy_foo()
{
global $foo;
unset($foo);
}
$foo = 'bar';
destroy_foo();
echo $foo;
?>
The above example will output:
bar
To unset(3) a global variable inside of a function, then use the $GLOBALS array to do so:
<?php
function foo()
{
unset($GLOBALS['bar']);
}
$bar = "something";
foo();
?>
If a variable that is PASSED BY REFERENCE is unset(3) inside of a function, only the local variable is destroyed. The variable in the
calling environment will retain the same value as before unset(3) was called.
<?php
function foo(&$bar)
{
unset($bar);
$bar = "blah";
}
$bar = 'something';
echo "$bar
";
foo($bar);
echo "$bar
";
?>
The above example will output:
something
something
If a static variable is unset(3) inside of a function, unset(3) destroys the variable only in the context of the rest of a function. Fol-
lowing calls will restore the previous value of a variable.
<?php
function foo()
{
static $bar;
$bar++;
echo "Before unset: $bar, ";
unset($bar);
$bar = 23;
echo "after unset: $bar
";
}
foo();
foo();
foo();
?>
The above example will output:
Before unset: 1, after unset: 23
Before unset: 2, after unset: 23
Before unset: 3, after unset: 23
PARAMETERS
o $var
- The variable to be unset.
o $...
- Another variable ...
RETURN VALUES
No value is returned.
EXAMPLES
Example #1
unset(3) example
<?php
// destroy a single variable
unset($foo);
// destroy a single element of an array
unset($bar['quux']);
// destroy more than one variable
unset($foo1, $foo2, $foo3);
?>
Example #2
Using (unset) casting
(unset) casting is often confused with the unset(3) function. (unset) casting serves only as a NULL-type cast, for completeness. It
does not alter the variable it's casting.
<?php
$name = 'Felipe';
var_dump((unset) $name);
var_dump($name);
?>
The above example will output:
NULL
string(6) "Felipe"
NOTES
Note
Because this is a language construct and not a function, it cannot be called using variable functions.
Note
It is possible to unset even object properties visible in current context.
Note
It is not possible to unset $this inside an object method since PHP 5.
Note
When using unset(3) on inaccessible object properties, the __unset() overloading method will be called, if declared.
SEE ALSO isset(3), empty(3), __unset(), array_splice(3).
PHP Documentation Group UNSET(3)