Grouping element array php based first character value - php

Question

I have an array based MySql database.
This is the array.
[
0 => [
'id' => '1997'
'lokasi_terakhir' => 'YA4121'
]
1 => [
'id' => '1998'
'lokasi_terakhir' => 'PL2115'
]
2 => [
'id' => '1999'
'lokasi_terakhir' => 'PL4111'
]
]
How can I get the element lokasi_terakhir that grouped by the first character ? What the best way ?
This is the goal :
[
"Y" => 1,
"P" => 2
]
Please advise

Answer 1

Here are two refined methods. Which one you choose will come down to your personal preference (you won't find better methods).
In the first, I am iterating the array, declaring the first character of the lokasi_terakhir value as the key in the $result declaration. If the key doesn't yet exist in the output array then it must be declared / set to 1. After it has been instantiated, it can then be incremented -- I am using "pre-incrementation".
The second method first maps a new array using the first character of the lokasi_terakhir value from each subarray, then counts each occurrence of each letter.
(Demonstrations Link)
Method #1: (foreach)
foreach($array as $item){
if(!isset($result[$item['lokasi_terakhir'][0]])){
$result[$item['lokasi_terakhir'][0]]=1; // instantiate
}else{
++$result[$item['lokasi_terakhir'][0]]; // increment
}
}
var_export($result);
Method #2: (functional)
var_export(array_count_values(array_map(function($a){return $a['lokasi_terakhir'][0];},$array)));
// generate array of single-character elements, then count occurrences
Output: (from either)
array (
'Y' => 1,
'P' => 2,
)

Answer 2

You can group those items like this:
$array = [
0 => [
'id' => '1997',
'lokasi_terakhir' => 'YA4121'
],
1 => [
'id' => '1998',
'lokasi_terakhir' => 'PL2115'
],
2 => [
'id' => '1999',
'lokasi_terakhir' => 'PL4111'
]
];
$result = array();
foreach($array as $item) {
$char = substr($item['lokasi_terakhir'], 0, 1);
if(!isset($result[$char])) {
$result[$char] = array();
}
$result[$char][] = $item;
}

Answer 3

<?php
$array=[
0 => [
'id' => '1997',
'lokasi_terakhir' => 'YA4121'
],
1 => [
'id' => '1998',
'lokasi_terakhir' => 'PL2115'
],
2 => [
'id' => '1999',
'lokasi_terakhir' => 'PL4111'
]
];
foreach($array as $row){
$newArray[]=$row['lokasi_terakhir'][0];
}
print_r(array_flip(array_unique($newArray)));
this code gets the first letter of the fields lokasi_terakhir , get the unique values to avoid duplicates and just flips the array to get the outcome you want.
The output is this :
Array ( [Y] => 0 [P] => 1 )