I would like to know how I can use the php extract function to extract the key from an array to change variables snake_case to camel_case.
Example:
array('id' => 1, 'user_name' => 'Paul');
To
$id = 1;
$userName = 'Paul';
I'm using laravel framework.
Thanks;)
foreach($array as $key => $value) {
$name = camel_case($key);
$$name = $value;
}
You can't with extract.
Quoting the PHP Manual (emphasis mine):
array: An associative array. This function treats keys as variable names and values as variable values. For each key/value pair it will create a variable in the current symbol table, subject to flags and prefix parameters.
There is no flag to change the case of the keys. It will use the array key as it appears in the array for the variable name. If you want camel case, you need to change the array key. There is no other way with extract.
You could do this in userland with this piece of code:
$data = array('id' => 1, 'user_name' => 'Paul');
foreach ($data as $k => $v) {
${lcfirst(str_replace('_', '', ucwords($k, '_')))} = $v;
}
echo $userName;
And apparently, Laravel has a helper function for that doing roughly the same under the hood.
But seriously… don't. That's very pointless to do. It's a complete waste of CPU to transform the key to camel case. Just use $user_name or $data['user_name'].
Related
I have an array like this:
array(
'firstName' => 'Joe',
'lastName' => 'Smith'
)
I need to loop over every element in my array and in the end, the array should look like this:
array(
'FirstName' => 'Joe',
'LastName' => 'Smith'
)
Failed idea was:
foreach($array as $key => $value)
{
$key = ucfirst($key);
}
This obviously will not work, because the array is not passed by reference. However, all these attempts also fail:
foreach(&$array as $key => $value)
{
$key = ucfirst($key);
}
foreach($array as &$key => $value)
{
$key = ucfirst($key);
}
Pretty much at my wits end with this one. I'm using Magento 1.9.0.1 CE, but that's pretty irrelevant for this problem. If you must know, the reason I have to do this is because I have a bunch of object that's I'm returning as an array to be assembled into a SOAP client. The API I'm using requires the keys to begin with a capital letter...however, I don't wish to capitalize the first letter of my object's variable names. Silly, I know, but we all answer to someone, and that someone wants it that way.
unset it first in case it is already in the proper format, otherwise you will remove what you just defined:
foreach($array as $key => $value)
{
unset($array[$key]);
$array[ucfirst($key)] = $value;
}
You can't modify the keys in a foreach, so you would need to unset the old one and create a new one. Here is another way:
$array = array_combine(array_map('ucfirst', array_keys($array)), $array);
Get the keys using array_keys
Apply ucfirst to the keys using array_map
Combine the new keys with the values using array_combine
The answers here are dangerous, in the event that the key isn't changed, the element is actually deleted from the array. Also, you could unknowingly overwrite an element that was already there.
You'll want to do some checks first:
foreach($array as $key => $value)
{
$newKey = ucfirst($key);
// does this key already exist in the array?
if(isset($array[$newKey])){
// yes, skip this to avoid overwritting an array element!
continue;
}
// Is the new key different from the old key?
if($key === $newKey){
// no, skip this since the key was already what we wanted.
continue;
}
$array[$newKey] = $value;
unset($array[$key]);
}
Of course, you'll probably want to combine these "if" statements with an "or" if you don't need to handle these situations differently.
This might work:
foreach($array as $key => $value) {
$newkey = ucfirst($key);
$array[$newkey] = $value;
unset($array[$key]);
}
but it is very risky to modify an array like this while you're looping on it. You might be better off to store the unsettable keys in another array, then have a separate loop to remove them from the original array.
And of course, this doesn't check for possible collisions in the aray, e.g. firstname -> FirstName, where FirstName already existed elsewhere in the array.
But in the end, it boils down to the fact that you can't "rename" a key. You can create a new one and delete the original, but you can't in-place modify the key, because the key IS the key to lookup an entry in the aray. changing the key's value necessarily changes what that key is pointing at.
Top of my head...
foreach($array as $key => $value){
$newKey = ucfirst($key);
$array[$newKey] = $value;
unset($array[$key]);
}
Slightly change your way of thinking. Instead of modifying an existing element, create a new one, and remove the old one.
If you use laravel or have Illuminate\Support somewhere in your dependencies, here's a chainable way:
>>> collect($array)
->keys()
->map(function ($key) {
return ucfirst($key);
})
->combine($array);
=> Illuminate\Support\Collection {#1389
all: [
"FirstName" => "Joe",
"LastName" => "Smith",
],
}
I am calling a function like:
get(array('id_person' => $person, 'ot' => $ot ));
In function How can I access the key and value as they are variable?
function get($where=array()) {
echo where[0];
echo where[1];
}
How to extract 'id_person' => $person, 'ot' => $ot without using foreach as I know how many key-values pairs I have inside function?
You can access them via $where['id_person'] / $where['ot'] if you know that they will always have these keys.
If you want to access the first and second element, you can do it like this
reset($where)
$first = current($where);
$second = next($where);
Couple ways. If you know what keys to expect, you can directly address $where['id_person']; Or you can extract them as local variables:
function get($where=array()) {
extract($where);
echo $id_person;
}
If you don't know what to expect, just loop through them:
foreach($where AS $key => $value) {
echo "I found $key which is $value!";
}
Just do $where['id_person'] and $where['ot'] like you do in JavaScript.
If you do not care about keys and want to use array as ordered array you can shift it.
function get($where=array()) {
$value1 = array_shift($where);
$value2 = array_shift($where);
}
I can't find an answer to this anywhere.
foreach ($multiarr as $array) {
foreach ($array as $key=>$val) {
$newarray[$key] = $val;
}
}
say $key has duplicate names, so when I am trying to push into $newarray it actually looks like this:
$newarray['Fruit'] = 'Apples';
$newarray['Fruit'] = 'Bananas';
$newarray['Fruit'] = 'Oranges';
The problem is, the above example just replaces the old value, instead of pushing into it.
Is it possible to push values like this?
Yes, notice the new pair of square brackets:
foreach ($multiarr as $array) {
foreach ($array as $key=>$val) {
$newarray[$key][] = $val;
}
}
You may also use array_push(), introducing a bit of overhead, but I'd stick with the shorthand most of the time.
I'll offer an alternative to moonwave99's answer and explain how it is subtly different.
The following technique unpacks the indexed array of associative arrays and serves each subarray as a separate parameter to array_merge_recursive() which performs the merging "magic".
Code: (Demo)
$multiarr = [
['Fruit' => 'Apples'],
['Fruit' => 'Bananas'],
['Fruit' => 'Oranges'],
['Veg' => 'Carrot'],
//['Veg' => 'Leek'],
];
var_export(
array_merge_recursive(...$multiarr)
);
As you recursively merge, if there is only one value for a respective key, then a subarray is not used, if there are multiple values for a key, then a subarray is used.
See this action by uncommenting the Leek element.
p.s. If you know that you are only targetting a single column of data and you know the key that you are targetting, then array_column() would be a wise choice.
Code: (Demo)
var_export(
['Fruit' => array_column($multiarr, 'Fruit')]
);
This is the set of result from my database
print_r($plan);
Array
(
[0] => Array
(
[id] => 2
[subscr_unit] => D
[subscr_period] =>
[subscr_fee] =>
)
[1] => Array
(
[id] => 3
[subscr_unit] => M,Y
[subscr_period] => 1,1
[subscr_fee] => 90,1000
)
[2] => Array
(
[id] => 32
[subscr_unit] => M,Y
[subscr_period] => 1,1
[subscr_fee] => 150,1500
)
)
How can I change the $plan[0] to $plan[value_of_id]
Thank You.
This won't do it in-place, but:
$new_plan = array();
foreach ($plan as $item)
{
$new_plan[$item['id']] = $item;
}
This may be a bit late but I've been looking for a solution to the same problem. But since all of the other answers involve loops and are too complicated imho, I've been trying some stuff myself.
The outcome
$items = array_combine(array_column($items, 'id'), $items);
It's as simple as that.
You could also use array_reduce which is generally used for, well, reducing an array. That said it can be used to achieve an array format like you want by simple returning the same items as in the input array but with the required keys.
// Note: Uses anonymous function syntax only available as of PHP 5.3.0
// Could use create_function() or callback to a named function
$plan = array_reduce($plan, function($reduced, $current) {
$reduced[$current['id']] = $current;
return $reduced;
});
Note however, if the paragraph above did not make it clear, this approach is overkill for your individual requirements as outlined in the question. It might prove useful however to readers looking to do a little more with the array than simply changing the keys.
Seeing the code you used to assemble $plan would be helpful, but I'm going assume it was something like this
while ($line = $RES->fetch_assoc()) {
$plan[] = $line;
}
You can simply assign an explicit value while pulling the data from your database, like this:
while ($line = $RES->fetch_assoc()) {
$plan[$line['id']] = $line;
}
This is assuming $RES is the result set from your database query.
In my opinion, there is no simpler or more expressive technique than array_column() with a null second parameter. The null parameter informs the function to retain all elements in each subarray, the new 1st level keys are derived from the column nominated in the third parameter of array_column().
Code: (Demo)
$plan = array_column($plan, null, 'id');
Note: this technique is also commonly used to ensure that all subarrays contain a unique value within the parent array. This occurs because arrays may not contain duplicate keys on the same level. Consequently, if a duplicate value occurs while using array_column(), then previous subarrays will be overwritten by each subsequent occurrence of the same value to be used as the new key.
Demonstration of "data loss" due to new key collision.
$plans = array();
foreach($plan as $item)
{
$plans[$item['id']] = $item;
}
$plans contains the associative array.
This is just a simple solution.
$newplan = array();
foreach($plan as $value) {
$id = $value["id"];
unset($value["id"]);
$newplan[$id] = $value;
}
What does the => operator mean in the following code?
foreach ($user_list as $user => $pass)
The code is a comment at PHP.net.
The user does not specify the value of $user_list, $user or $pass.
I normally see that => means equal or greater than.
However, I am not sure about its purpose here because it is not assigned.
I read the code as
process a list of users in integers
such that the value of each user is equal or greater than password
The above does not make sense to me.
=> is the separator for associative arrays. In the context of that foreach loop, it assigns the key of the array to $user and the value to $pass.
Example:
$user_list = array(
'dave' => 'apassword',
'steve' => 'secr3t'
);
foreach ($user_list as $user => $pass) {
echo "{$user}'s pass is: {$pass}\n";
}
// Prints:
// "dave's pass is: apassword"
// "steve's pass is: secr3t"
Note that this can be used for numerically indexed arrays too.
Example:
$foo = array('car', 'truck', 'van', 'bike', 'rickshaw');
foreach ($foo as $i => $type) {
echo "{$i}: {$type}\n";
}
// prints:
// 0: car
// 1: truck
// 2: van
// 3: bike
// 4: rickshaw
It means assign the key to $user and the variable to $pass
When you assign an array, you do it like this
$array = array("key" => "value");
It uses the same symbol for processing arrays in foreach statements. The '=>' links the key and the value.
According to the PHP Manual, the '=>' created key/value pairs.
Also, Equal or Greater than is the opposite way: '>='. In PHP the greater or less than sign always goes first: '>=', '<='.
And just as a side note, excluding the second value does not work like you think it would. Instead of only giving you the key, It actually only gives you a value:
$array = array("test" => "foo");
foreach($array as $key => $value)
{
echo $key . " : " . $value; // Echoes "test : foo"
}
foreach($array as $value)
{
echo $value; // Echoes "foo"
}
Code like "a => b" means, for an associative array (some languages, like Perl, if I remember correctly, call those "hash"), that 'a' is a key, and 'b' a value.
You might want to take a look at the documentations of, at least:
foreach
arrays
Here, you are having an array, called $user_list, and you will iterate over it, getting, for each line, the key of the line in $user, and the corresponding value in $pass.
For instance, this code:
$user_list = array(
'user1' => 'password1',
'user2' => 'password2',
);
foreach ($user_list as $user => $pass)
{
var_dump("user = $user and password = $pass");
}
Will get you this output:
string 'user = user1 and password = password1' (length=37)
string 'user = user2 and password = password2' (length=37)
(I'm using var_dump to generate a nice output, that facilitates debuging; to get a normal output, you'd use echo)
"Equal or greater" is the other way arround: "greater or equals", which is written, in PHP, like this; ">="
The Same thing for most languages derived from C: C++, JAVA, PHP, ...
As a piece of advice: If you are just starting with PHP, you should definitely spend some time (maybe a couple of hours, maybe even half a day or even a whole day) going through some parts of the manual :-)
It'd help you much!
An array in PHP is a map of keys to values:
$array = array();
$array["yellow"] = 3;
$array["green"] = 4;
If you want to do something with each key-value-pair in your array, you can use the foreach control structure:
foreach ($array as $key => $value)
The $array variable is the array you will be using. The $key and $value variables will contain a key-value-pair in every iteration of the foreach loop. In this example, they will first contain "yellow" and 3, then "green" and 4.
You can use an alternative notation if you don't care about the keys:
foreach ($array as $value)
Arrays in PHP are associative arrays (otherwise known as dictionaries or hashes) by default. If you don't explicitly assign a key to a value, the interpreter will silently do that for you. So, the expression you've got up there iterates through $user_list, making the key available as $user and the value available as $pass as local variables in the body of the foreach.
$user_list is an array of data which when looped through can be split into it's name and value.
In this case it's name is $user and it's value is $pass.