How to get key value of array? [duplicate] - php

This question already has answers here:
Getting the key of the only element in a PHP array
(6 answers)
Closed 8 years ago.
How do I get the value of a key of any array item? Like how a foreach loop turns it into $k => $v...except I only want to do that once, so no need for a loop. Do I really need to make a new array that it flips to?
Take this for example.
1 => array(
'street' => 'Street Address ',
'town' => 'Town/City '
),
2 => array(
'state' => 'State '
),
Those are arrays inside a bigger array. And now I tried to do this
array_flip($thatarrayupthere[2]['state'])
What I want to receive from that is "state" because that is the key name. But I'm getting errors.

I'm not exactly sure what you wan't, but if you just want to get the key of the second array in any given array this might help.
$key = key($array[2]);
In your example above you will get "state" in your $key variable.

$key = array_keys($array[2]);
print_r($key);
ref: http://php.net/manual/en/function.array-keys.php

Related

Group data by first element of 2 dimensional array - PHP [duplicate]

This question already has answers here:
Prevent array overwriting and instead create new array index
(2 answers)
Closed 2 years ago.
I have this code.
$shirts = [
['xl','silk','blue'],
['xl', 'cotton', 'red'],
['L', 'silk', 'green'],
['L', 'silk', 'black']
];
I want to group size . For example, I want output like this
$shirtbysize = [
'xl' =>
[
['silk','blue'],
['cotton','red']
],
'L' =>
[
['silk','green'],
['silk','black']
],
];
I searched everywhere but I didn't get answer. Can anyone tell me how to do this?
Use array_shift to pick the first element and remove it from array.
array_shift() shifts the first value of the array off and returns it, shortening the array by one element and moving everything down. All numerical array keys will be modified to start counting from zero while literal keys won't be affected.
Use array_shift to pick the first element and set it as index.
Now first element is already removed from first step, set the remaining array as data to above index.
$shirtbysize = [];
foreach($shirts as $shirt){
$shirtbysize[array_shift($shirt)][] = $shirt;
}

How to merge two arrays into one and transpose the structure to simplify printing from a loop? [duplicate]

This question already has answers here:
Merge row data from multiple arrays
(6 answers)
Closed 4 months ago.
How can I combine 2 arrays ... :
$array_1 = [['title' => 'Google'], ['title' => 'Bing']];
$array_2 = [['link' => 'www.example1.com'], ['link' => 'www.example2.com']];
In order to get ... :
$array_3 = [
['title' => 'Google', 'link' => 'www.example1.com'],
['title' => 'Bing', 'link' => 'www.example2.com']
];
I guess $array_3 should be structured the following way in order to get :
Final result:
Google - See website
Bing - See website
The function to get the final result:
function site_and_link($array_3) {
foreach ($array_3 as $a) {
echo $a['title'] . " - See website</br>";
}
}
What is the missing step to arrange $array_3?
You can use a simple foreach loop and array_merge to merge both subarrays.
<?php
$result = [];
foreach($array_1 as $index => $val){
$result[] = array_merge($val,$array_2[$index]);
}
print_r($result);
It is indirect programming to use a loop to merge-transpose your array data, then another loop to print to screen.
Ideally, you should try to merge these structures earlier in your code if possible (I don't know where these datasets are coming from, so I cannot advise.)
Otherwise, leave the two arrays unmerged and just write a single loop to print to screen. Because the two arrays are expected to relate to each other by their indexes, there will be no risk of generating Notices.
Since I am typing this out, I'll take the opportunity to reveal a couple of useful tricks:
You can unpack your single-element subarrays by using array syntax with a static key pointing to the targeted variable in the foreach().
Using printf() can help to cut down on line bloat/obfuscation caused by concatenation/interpolation. By writing placeholders (%s) into the string and then passing values for those placeholders in the trailing arguments, readablity is often improved.
Code: (Demo)
$sites = [['title' => 'Google'], ['title' => 'Bing']];
$links = [['link' => 'www.example1.com'], ['link' => 'www.example2.com']];
foreach ($sites as $index => ['title' => $title]) {
printf(
'%s - See website</br>',
$title,
$links[$index]['link']
);
}
Output:
Google - See website</br>
Bing - See website</br>

php sort multidimensional array by specific key [duplicate]

This question already has answers here:
sort a multi-dimensional associative array?
(3 answers)
Closed 5 years ago.
i have seen several SO answers but none seem to address this very simple situation.
my array looks like the following:
$myArray =
['person_1#gmail.com'] =>
['2017-01-05'] =>
'this is line one'
'this is line two'
['2016-05-05'] =>
'this is another line'
'and this is a fourth line'
['2017-07-10'] =>
'more lines'
'yet another line'
['person_2#gmail.com'] =>
['2015-01-01'] =>
'line for person_2'
within each of the first levels (email address), how would I sort the second level (date yyyy-mm-dd) in descending?
I did try this:
foreach ( $myArray as $emailAddress => $emailAddressArrayOfDates ) {
usort ( $myArray[$emailAddress] );
}
and I also tried to ksort with a function as well with no success.
thank you very much.
Use this:
foreach($myArray as $emailAddressKey=>$datesArray){
krsort($myArray[$emailAddressKey]);
}
print_r($myArray);
or (but i prefer the first option)
foreach($myArray as &$value){
krsort($value);
// this works only if $value is passed by reference. If it's not,
// it will update $value, but not $myArray[$key] as $value is only
// a local variable.
}
print_r($myArray);
This is the sorting method:
krsort — Sort an array by key in reverse order
bool krsort ( array &$array [, int $sort_flags = SORT_REGULAR ] )
See a working example here: https://3v4l.org/pok2e

how to use array_push() [duplicate]

This question already has answers here:
Add values to an associative array in PHP
(2 answers)
Closed 7 years ago.
I want to push new data in array which each value of them.
$array = array("menu1" => "101", "menu2" => "201");
array_push($array, "menu3" => "301");
But I got an error syntax.
And if I use like this :
$array = array("menu1" => "101", "menu2" => "201");
array_push($array, "menu3", "301");
result is : Array ( [menu1]=>101 [menu2]=>201 [0]=>menu3 [1]=>301 )
My hope the result is : Array ( [menu1]=>101 [menu2]=>201 [menu3]=>301 )
I want push new [menu3]=>'301' but I dont know how. Please help me, the answer will be appreciate
You can use
$array["menu3"] = "301"
as for array_push
array_push() treats array as a stack, and pushes the passed variables onto the end of array
so for associative arrays is a no match
another suitable function for what you want but it requires an array argument is array_merge
$result = array_merge(array("one" => "1"), array("two" => "2"));

Why is this PHP array not the same? [duplicate]

This question already has answers here:
How can I access an array/object?
(6 answers)
Closed 4 months ago.
I'm not understanding why the array:
<? $data = array( 'items[0][type]' => 'screenprint'); ?>
Is not the same as
<? echo $data['items'][0]['type']; ?>
I'm trying to add to the array but can't seem to figure out how?
array( 'items[0][type]' => 'screenprint')
This is an array which has one key which is named "items[0][type]" which has one value. That's not the same as an array which has a key items which has a key 0 which has a key type. PHP doesn't care that the key kinda looks like PHP syntax, it's just one string. What you want is:
$data = array('items' => array(0 => array('type' => 'screenprint')));
I hope it's obvious that that's a very different data structure.
It should be:
$data = [
'items' => [['type' => 'screenprint']]
];
echo $data['items'][0]['type'];

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