This is what I have:
$namex = $xml->xpath("//a[#b=foo]/c");
$name = $namex[0];
echo $name;
It works, as the first line creates an array and the second line reads the first entry. Is there a way to combine the two lines to get the intended result right away?
You can use list:
list($name) = $xml->xpath("//a[#b=foo]/c");
Is there a way to combine the two lines to get the intended result right away?
Yes and no...
PHP 5.4+:
echo $xml->xpath("//a[#b=foo]/c")[0]; // array dereferencing, yay!
PHP < 5.4:
$names = $xml->xpath("//a[#b=foo]/c");
echo $names[0];
Related
what I have to change to this part will work?
$array4Midfeld = array('$LM', '$DMEins', '$DMZwei', '$RM');
$array4Midfield[0] = "Test";
At the moment I get an error, regarding to the second line.
Error is... $LM not defined.
There is spelling mistake in array name on line number 2.
You have created array with $array4Midfeld name and accessing it with
$array4Midfield name on line number 2. That's why you are getting error.
try following code, It is working.
<?php
$array4Midfield = array($LM, $DMEins, $DMZwei, $RM);
$array4Midfield[0] = "Test";
print_r($array4Midfield);
?>
You have two problems with this:
Are you assigning variables as elements of the array? (ie $LM, $DMZwei, etc), or are they text? "$LM", "$DMZwei"
Your variables are not the same. Line 1 and Line 2 are two different vars: array4Midfeld and array4Midfield, are they supposed to be the same?
So are you testing that
`$array4Midfield[0] = "Test"
or
`$array4Midfield[0] = $LM
or
$LM = "Test"
Please assign Values to an array in this form. More over the array name too, am confuse whether they are the same or not. $array4Mittelfeld or $array4Midfield
$array4Mittelfield[0] = $LM;
$array4Mittelfield[1] = $DMEins;
$array4Mittelfield[2] = $DMZwei;
$array4Mittelfield[3] = $RM;
echo $array4Mittelfield[0];
or you can use loop to print all the values
Hope it helps
I'm getting the following warning when running this script:
Warning: Invalid argument supplied for foreach()
This is the script:
$values = array();
foreach ($_POST['rights'] as $right_id)
{
$values[] = '(' . $id . ', ' . $right_id . ')';
}
$_POST['rights']/$id are integers. In this case it was $_POST['rights'] = 1,2,3,4,5; $id = 2.
The strange part is that on a different page with the same kind of input it gives no errors.
The question: What is wrong with it?
check $_POST['rights']
var_dump($_POST['rights']);
I think $_POST['rights'] is not an array.
foreach must take an array, you're passing it an integer. You can't iterate over an integer.
A wise move might be to check whatever you're about to iterate over is indeed an array:
if(is_array($_POST['rights'])){
foreach($_POST['rights'] as $value){
//Whatever you want to do with each $value
}
}
else {
//Let the user know it's hit the fan…
throw new Exception('Help, I\'m not an array :(')
}
PHP docs for arrays: http://php.net/manual/en/language.types.array.php
PHP docs for foreach: http://php.net/manual/en/control-structures.foreach.php
As per your statement $_POST['rights'] is not an array.
It is probably a simple string having 1,2,3,4
You need to convert it into an array with explode function.
e.g
$_POST['rights'] = explode(",", $_POST['rights']);
Then your for loop will work.
The passed array $_POST['rights'] probably is empty.
EDIT:
Like Mark Baker said an empty array is fine. You should go with the other answers.
In the PHP manual, (array_push) says..
If you use array_push() to add one element to the array it's better to
use $array[] = because in that way there is no overhead of calling a
function.
For example :
$arr = array();
array_push($arr, "stackoverflow");
print_r($arr);
vs
$arr[] = "stackoverflow";
print_r($arr);
I don't understand why there is a big difference.
When you call a function in PHP (such as array_push()), there are overheads to the call, as PHP has to look up the function reference, find its position in memory and execute whatever code it defines.
Using $arr[] = 'some value'; does not require a function call, and implements the addition straight into the data structure. Thus, when adding a lot of data it is a lot quicker and resource-efficient to use $arr[].
You can add more than 1 element in one shot to array using array_push,
e.g. array_push($array_name, $element1, $element2,...)
Where $element1, $element2,... are elements to be added to array.
But if you want to add only one element at one time, then other method (i.e. using $array_name[]) should be preferred.
The difference is in the line below to "because in that way there is no overhead of calling a function."
array_push() will raise a warning if the first argument is not
an array. This differs from the $var[] behaviour where a new array is
created.
You should always use $array[] if possible because as the box states there is no overhead for the function call. Thus it is a bit faster than the function call.
array_push — Push one or more elements onto the end of array
Take note of the words "one or more elements onto the end"
to do that using $arr[] you would have to get the max size of the array
explain:
1.the first one declare the variable in array.
2.the second array_push method is used to push the string in the array variable.
3.finally it will print the result.
4.the second method is directly store the string in the array.
5.the data is printed in the array values in using print_r method.
this two are same
both are the same, but array_push makes a loop in it's parameter which is an array and perform $array[]=$element
Thought I'd add to the discussion since I believe there exists a crucial difference between the two when working with indexed arrays that people should be aware of.
Say you are dynamically creating a multi-dimensional associative array by looping through some data sets.
$foo = []
foreach ($fooData as $fooKey => $fooValue) {
foreach ($fooValue ?? [] as $barKey => $barValue) {
// Approach 1: results in Error 500
array_push($foo[$fooKey], $barKey); // Error 500: Argument #1 ($array) must be of type array
// NOTE: ($foo[$fooKey] ?? []) argument won't work since only variables can be passed by reference
// Approach 2: fix problem by instantiating array beforehand if it didn't exist
$foo[$fooKey] ??= [];
array_push($foo[$fooKey], $barKey);
// Approach 3: One liner approach
$foo[$fooKey][] = $barKey; // Instantiates array if it doesn't exist
}
}
Without having $foo[$fooKey] instantiated as an array beforehand, we won't be able to do array_push without getting the Error 500. The shorthand $foo[$fooKey][] does the heavy work for us, checking if the provided element is an array, and if it isn't, it creates it and pushes the item in for us.
I know this is an old answer but it might be helpful for others to know that another difference between the two is that if you have to add more than 2/3 values per loop to an array it's faster to use:
for($i = 0; $i < 10; $i++){
array_push($arr, $i, $i*2, $i*3, $i*4, ...)
}
instead of:
for($i = 0; $i < 10; $i++){
$arr[] = $i;
$arr[] = $i*2;
$arr[] = $i*3;
$arr[] = $i*4;
...
}
edit- Forgot to close the bracket for the for conditional
No one said, but array_push only pushes a element to the END OF THE ARRAY, where $array[index] can insert a value at any given index. Big difference.
I have a cookie which I'm trying to split. The cookie is in this format:
key = val1,val2,val3 (where each value is separated by commas)
is there a way for me to split this in a loop so that I can directly access val3?
I've tried using the explode() function with no success.
for ($i = 0; $i < count($_COOKIE); $i++)
{
$ind = key($_COOKIE);
$data = $_COOKIE[$ind];
//I try and slit the cookie here
$cookie_temp = explode(",",$_COOKIE[$ind]);
//Here is where I wanted to display Val3 from the cookie
print $cookie_temp[2];
next($_COOKIE);
}
my code works fine but I then end up with all my Val3 in a large array. For example, my val3's are numbers and they get put in an array. Can I split this even further?
First of all, I'm hoping you know the name of the cookie you're trying to get the value of. Let's call it mycookie in the rest of my answer.
Second, just scrap the whole loop thing and just access $_COOKIE['mycookie'] directly.
Then, you can now call explode(",",$_COOKIE['mycookie']) to get the separate values.
Next, just get index 2 with [2] as you are in your current code.
As a shortcut, if the second one is the only one you need:
list(,,$val) = explode(",",$_COOKIE['mycookie']);
Assuming you are looping because you have multiple comma-separated cookie key/value groups, use a foreach() instead and with list() you can retrieve the third value with a direct assignment.
foreach ($_COOKIE as $key=>$value) {
list($v1, $v2, $v3) = explode("," $value);
echo $v3;
}
If you have only one cookie value to access, there is no need for the loop, and you can directly call explode(",", $_COOKIE['key'])
PHP 5.4 allows array dereferencing, whereby you can directly access the array element off of the explode() call, but this won't work in earlier PHP versions.
echo explode(",", $_COOKIE['key'])[2];
Why won't this work?
$slidetotal=1;
$slideids = array();
while ($rowcs = mysql_fetch_array($orig_slides_result)) {
$key = $slidetotal;
array_push($slideids[$key], $rowcs['id']);
$slidetotal++;
}
I get this error:
[phpBB Debug] PHP Notice: in file ///*.php on line 161: array_push() [function.array-push]: First argument should be an array
Although someone has commented you can do this on this page:
http://php.net/manual/en/function.array-push.php , (find: "to insert a "$key" => "$value" pair into an array")
What is the next best way to insert a list of single values into a php array? By the way, I really can't believe it's hard to find something on this with google.com. Seriously?
That PHP.net comment is incorrect. That is pushing $rowcs['id'] onto the array $slideids[$key], not the array $slideids.
You should be doing the following, in place of your array_push() call:
$slideids[$key] = $rowcs['id'];
Why don't you do;
$slidetotal=1;
$slideids = array();
while ($rowcs = mysql_fetch_array($orig_slides_result)) {
$slideids[$slidetotal] = $rowcs['id'];
$slidetotal++;
}
Also you can do like below if you don't need the key to start from 1;
$slideids = array();
while ($rowcs = mysql_fetch_array($orig_slides_result)) {
$slideids[] = $rowcs['id'];
}
ummm hard-searching will work for google I think :)
anyway, error tells you everything you need to know. that means first argument of array_push is not an array, you give a single value (string) to array_push ($slideids[$key]).
Also why do you need to use array_push in php? I'd rather use
$slideids[] = $rowcs['id'];
and what you're trying to do is:
$slideids[$key] = $rowcs['id'];
i guess...