Change variable value inside an array in a new array - php

How to, and is it possible to add different value to a variable inside an array, but to simplify it possibly to do it with another array; i need to store processes and their cpu load on my page, but since process names are "ugly", i need to change their name to something normal looking
so far i have managed to extract top 5 of them (mostly the same every time) like this:
$array[0] = "process1";
$array[1] = "process2";
$array[2] = "process3";
Now i want to add as many possibilities as possible to change some prettier values to them
$new_values = array(
"process1" == "Process name as i want it",
"process2" == "Second process"
);
So when i call say $array[1]
i don't get "process2" but changed name ("Second process")
Thanks in advance

You could do something like this, using the value from the first array as the key for the $new_values array:
echo $new_values[$array[1]]; // Second process
Edit: I'll wrap this inside a function to check for the $new_values existence, otherwise fall back to the original value:
function displayPretty($key) {
global $new_values; // get the $new_values array from global scope
if(array_key_exists($key, $new_values))
return $new_values[$key]; // return pretty name if it exists
return $key; // return original value otherwise
}
echo displayPretty($array[1]);
This way, if you pass in $array[1] it will return the value from $new_values if it exists (e.g. Second process in this case), and if it doesn't (e.g. if you passed in $array[5] and that doesn't have a pretty definition in $new_values) it will just return what you passed in.

Related

Looping through array : New variable for each Value

Lets say I have an array looking like this:
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30)
and a loop looking like this:
for($i=0;$i<count($sql);$i++){
$value[$i] = ($sql[$i]);
echo $value[$i];
}
I want the loop to iterate through the array and assign each value to a new variable.
In this code i tried to make it store the values in:
value1
value2
value3
But sadly this doesnt work, thus I am here seeking help.
Or is it a problem that i got an associative array instead of a numeric one?
I dont want to use this loop on this array only but on other arrays with different keys and length aswell.
Edit: I think I may have not wrote it cleary enough to tell you what i want to achieve:
I want to have three string values at the end of the loop not stored in an array:
Variable1 should contain "Peter"
Variable2 should contain "1"
Variable3 should contain "30"
Plus I want this loop to be dynamic, not only accepting this specific array but if I were to give it an array with 100 Values, I would want to have 100 different variables in which the values are stored.
Sorry for not being clear enough, I am still new at stackoverflow.
Going by your condition, assign each value to a new variable, I think what you want would be to use Variable variables. Here is an example:
<?php
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30);
$count = 1;
foreach ($sql as $value) {
$x = 'value'.$count;
$$x = $value; //here's the usage of Variable variables
$count++;
}
echo $value1.'<br/>';
echo $value2.'<br/>';
echo $value3.'<br/>';
I went to your sample variables ($value1, $value2, etc.). I also changed your loop to foreach to easily loop the array. And I also added a $count that will serve as the number of the $value variable.
The $count wouldn't be necessary if your index are numeric, but since its an associative array, something like this is needed to differentiate the variables created
A brief explanation as requested:
$x contains the name of the variable you want to create (in this case, value1), then when you add another $ to $x (which becomes $$x), you are assigning value to the current value of $x (this equals to $value1='Peter')
To dynamically define a variable use $$. Demo
$sql = array("name"=>"Peter", "active"=>1 , "age"=>30);
$index = 1;
foreach($sql as $value){
${"value" . $index++} = $value;
}

how to refrence a nested class value by array value

I think the best way to explain my question is to give an example. Say I have the following object.
$data=new stdClass;
$data->test=new stdClass;
$data->test->test2=6;
$data->s=array('b',6,7);
I want to know how I can read or change any value in the object given the key value as an array.
I know the below won't work:
function doSomething($inputArray1,$inputArray2) {
$data[ $inputArray1 ]; //6
$data[ $inputArray2 ]=4; //was array('b',6,7);
}
//someone else provided
doSomething( array('test','test2') , array('s') );
Changed to make clear that I do not know the values of the array personally so using
$data->test->test2; to get the 6 like I normally would won't work. Also do not know the array length.
Figured it out:
$parts=array('test','test2');
$ref=&$data;
foreach($parts as $part) {
if (is_array($ref)) {
$ref=&$ref[$part]; //refrence next level if array
} else {
$ref=&$ref->$part; //refrence next level if object
}
}
echo $ref; //show value refrenced by array
$ref=4; //change value refrenced by array(surprised this works instead of making $ref=4 and breaking the refrence)
unset($ref); //get rid of refrence to prevent accidental setting. Thanks #mpyw
As I noted in the comments, you need to access the object/arrays as intended.
Their notations are as follows;
Object: ->
Array: []
So, taking your $data array you've generated, you'd have to access the object/array combination as such:
echo $data->s[2];
Example/Demo
And if you were to access the initial test/test2 itteration (which is set as an object (->)), then you need to access it as an object:
echo $data->test->test2;

Find index of value in associative array in php?

If you have any array $p that you populated in a loop like so:
$p[] = array( "id"=>$id, "Name"=>$name);
What's the fastest way to search for John in the Name key, and if found, return the $p index? Is there a way other than looping through $p?
I have up to 5000 names to find in $p, and $p can also potentially contain 5000 rows. Currently I loop through $p looking for each name, and if found, parse it (and add it to another array), splice the row out of $p, and break 1, ready to start searching for the next of the 5000 names.
I was wondering if there if a faster way to get the index rather than looping through $p eg an isset type way?
Thanks for taking a look guys.
Okay so as I see this problem, you have unique ids, but the names may not be unique.
You could initialize the array as:
array($id=>$name);
And your searches can be like:
array_search($name,$arr);
This will work very well as native method of finding a needle in a haystack will have a better implementation than your own implementation.
e.g.
$id = 2;
$name= 'Sunny';
$arr = array($id=>$name);
echo array_search($name,$arr);
Echoes 2
The major advantage in this method would be code readability.
If you know that you are going to need to perform many of these types of search within the same request then you can create an index array from them. This will loop through the array once per index you need to create.
$piName = array();
foreach ($p as $k=>$v)
{
$piName[$v['Name']] = $k;
}
If you only need to perform one or two searches per page then consider moving the array into an external database, and creating the index there.
$index = 0;
$search_for = 'John';
$result = array_reduce($p, function($r, $v) use (&$index, $search_for) {
if($v['Name'] == $search_for) {
$r[] = $index;
}
++$index;
return $r;
});
$result will contain all the indices of elements in $p where the element with key Name had the value John. (This of course only works for an array that is indexed numerically beginning with 0 and has no “holes” in the index.)
Edit: Possibly even easier to just use array_filter, but that will not return the indices only, but all array element where Name equals John – but indices will be preserved:
$result2 = array_filter($p, function($elem) {
return $elem["Name"] == "John" ? true : false;
});
var_dump($result2);
What suits your needs better, resp. which one is maybe faster, is for you to figure out.

Calling PHP function in itself

In the following script function clean($data) calls it within it, that I understand but how it is cleaning data in the statement $data[clean($key)] = clean($value);??? Any help is appreciated.. I am trying to figure it out as I am new to PHP. Regards.
if (ini_get('magic_quotes_gpc')) {
function clean($data) {
if (is_array($data)) {
foreach ($data as $key => $value) {
$data[clean($key)] = clean($value);
}
} else {
$data = stripslashes($data);
}
return $data;
}
$_GET = clean($_GET);
$_POST = clean($_POST);
$_REQUEST = clean($_REQUEST);
$_COOKIE = clean($_COOKIE);
}
Your Question:
So if I undertsand correctly you want to know what is the function doing in the line
$data[clean($key)] = clean($value);
The Answer:
See the prime purpose of the function is to remove slashes from string with php's stripslashes method.
If the input item is an array then it tries to clean the keys of the array as well as the values of the array by calling itself on the key and value.
In php arrays are like hashmaps and you can iterate over the key and value both with foreach loop like following
foreach ($data as $key => $value) {....}
So if you want to summarize the algorithm in your code snippet it would be as under
Check if the input is array. If it is not then go to step 4
For each item of array clean the key and value by calling clean method on it (Recursively)
Return the array
clean the input string using stripslashes method
5 return the cleaned input
From my understanding it's not cleaning the key but creates a new element with a clean key while the uncleaned key remains.
$a['foo\bar'] : val\ue
becomes
$a['foo\bar'] : val\ue
$a['foobar'] : value
Someone correct me if im wrong.
Maybe you'll understand the code better if it's put this way:
foreach ($data as $key => $value) {
$key = clean($key); // Clean the key, the
$value = clean($value); // Clean the value
$data[$key] = $value; // Put it in the array that will be returned
}
Assuming you have an array like this:
$_POST = array(0 => 'foo', 1 => array('bar' => 'baz'));
the following will happen:
Call clean($_POST);
call clean 0
call clean 'foo'
$return[0] = 'foo'
call clean 1
call clean 'bar'
call clean 'baz'
$return[1] = array('bar' => 'baz');
You should probably read this: http://www.codewalkers.com/c/a/Miscellaneous/Recursion-in-PHP/
The main purpose of the function is to clean an associative array or a single variable. An associative array is an array where you define keys and values for that keys; so are special arrays used in PHP like $_GET $_POST and so on.
The meaning of "cleaning" is to check whether magic quotes are active - this causes some characters in these arrays to be escaped with backslashes when you post dynamic data to a PHP page.
$_GET["Scarlett"] = "O' Hara" becomes with magic quotes $_GET["Scarlett"] = "O\' Hara"
So if magic quotes are active, the function takes care of this, and slashes are stripped so that the strings retain their correct, not escaped value.
The algorithm checks if the data passed to the function is an array, if not it cleans directly the value.
$string = "Escapes\'in\'a string";
clean($string);
is it an array? No. Then return stripslashes(my data)
$array = array("key\'with\'escapes"=>"value\'with\'escapes", "another\'key"=>"another value");
clean($array)
is it an array? Yes. So cycle through each key/value pair with foreach, take the key and clean it like the first example; then take the value and do the same and put the cleaned versions in the array.
As you see the function has two different behaviours differentiated by that "if" statement.
If you pass an array, you activate the second behaviour that in turns passes couples of strings, not arrays, triggering the first behaviour.
My thought is that this function doesn't work properly, though. Anyone got the same sensation? I have it not tested yet but it seems it's not "cleaning" the key/values in the sense of replacing them, but adds the cleaned versions along the uncleaned ones.

Foreach value from POST from form

I post some data over to another page from a form. It's a shopping cart, and the form that's being submitted is being generated on the page before depending on how many items are in the cart. For example, if there's only 1 items then we only have the field name 'item_name_1' which should store a value like "Sticker" and 'item_price_1' which stores the price of that item. But if someone has 5 items, we would need 'item_name_2', 'item_name_3', etc. to get the values for each item up to the fifth one.
What would be the best way to loop through those items to get the values?
Here's what I have, which obviously isn't working.
extract($_POST);
$x = 1; // Assuming there's always one item we're on this page, we set the variable to get into the loop
while(${'item_name_' .$x} != '') {
echo ${'item_name' .$x};
$x++;
}
I'm still relatively new to this kind of usage, so I'm not entirely how the best way to deal with it.
Thanks.
First, please do not use extract(), it can be a security problem because it is easy to manipulate POST parameters
In addition, you don't have to use variable variable names (that sounds odd), instead:
foreach($_POST as $key => $value) {
echo "POST parameter '$key' has '$value'";
}
To ensure that you have only parameters beginning with 'item_name' you can check it like so:
$param_name = 'item_name';
if(substr($key, 0, strlen($param_name)) == $param_name) {
// do something
}
Use array-like fields:
<input name="name_for_the_items[]"/>
You can loop through the fields:
foreach($_POST['name_for_the_items'] as $item)
{
//do something with $item
}
If your post keys have to be parsed and the keys are sequences with data, you can try this:
Post data example: Storeitem|14=data14
foreach($_POST as $key => $value){
$key=Filterdata($key); $value=Filterdata($value);
echo($key."=".$value."<br>");
}
then you can use strpos to isolate the end of the key separating the number from the key.
i wouldn't do it this way
I'd use name arrays in the form elements
so i'd get the layout
$_POST['field'][0]['name'] = 'value';
$_POST['field'][0]['price'] = 'value';
$_POST['field'][1]['name'] = 'value';
$_POST['field'][1]['price'] = 'value';
then you could do an array slice to get the amount you need

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