Remove from array past dates - php

Question

I have the following array with different mixed dates from different years
Array
(
[0] => 2016-05-18
[1] => 2016-06-18
[2] => 2016-08-13
[3] => 2016-09-03
[4] => 2016-10-08
[5] => 2016-08-06
[6] => 2016-09-30
[7] => 2016-09-10
[8] => 2016-07-09
[9] => 2016-06-13
[10] => 2016-06-15
[11] => 2016-07-30
[12] => 2016-08-27
[13] => 2016-07-02
[14] => 2016-11-01
[15] => 2016-09-18
[16] => 2016-11-06
[17] => 2016-11-07
[18] => 2017-06-17
[19] => 2017-06-22
[20] => 2017-06-21
[21] => 2017-10-01
[22] => 2017-07-08
[23] => 2017-05-27
[24] => 2017-06-06
[25] => 2017-09-09
[26] => 2017-04-16
[27] => 2017-09-16
[28] => 2017-07-29
[29] => 2017-08-05
[30] => 2017-09-03
[31] => 2017-06-24
[32] => 2017-08-26
[33] => 2017-07-22
[34] => 2018-05-28
[35] => 2018-06-09
[36] => 2017-10-16
[37] => 2017-10-28
[38] => 2017-10-08
[39] => 2017-11-04
[40] => 2018-06-20
[41] => 2018-08-05
[42] => 2018-09-03
[43] => 2018-06-16
[44] => 2018-03-31
[45] => 2019-05-25
[46] => 2021-05-25
[47] => 2021-05-26
[48] => 2021-05-27
)
I want to remove all dates earlier than 2021 so my new array will have only the dates belonging to the current year of 2021. How can I filter the new array so all dates before 2021 will disappear?
Array
(
[0] => 2021-05-25
[1] => 2021-05-26
[2] => 2021-05-27
)

Answer 1

You can create a function that loops through the array and check if the string stars with 2021 if not, delete the element.
For php 8 you can use function:
str_starts_with(string $haystack, string $needle): bool
For example:
foreach($array as $key => $val){
if(!str_starts_with('2021', $val)){
unset($array[$key]);
}
}
For previous php versions you can use strpos
Example:
foreach($array as $key => $val){
if (!strpos($val, '2021') == 0) {
unset($array[$key]);
}
}

Answer 2

You have hashtag array-filter and PHP has array_filter function:
$dates = [
'2016-05-18',
'2018-03-31',
'2019-05-25',
'2021-05-25',
'2021-05-26',
'2021-05-27',
];
function myFilter($dt) {
$year = date('Y',strtotime($dt));
return $year > 2020;
}
print_r(array_values(array_filter($dates, 'myFilter')));

Answer 3

You can loop over each date and use the dateTime object to compare the times to see if the date has passed a set date like the begining of a year and if it hasn't then add it to the new array. See below code:
<?php
//array with mixed date data
$dateArray = array("2021-01-01","2016-05-18","2017-09-03","2018-06-16","2019-05-25","2021-05-25","2021-05-26","2021-05-27");
//the day you want to have everyday after (in this case the start of 2021)
$setDate = "2021-01-01";
//array where the dates greater than then the set date will be stored.
$newTimesArray = array();
$setDateObj = new \DateTime($setDate); // moved outside of loop
foreach ($dateArray as $date) {
$given_date = new \DateTime($date); //convert string to a date time object
if ($given_date >= $setDateObj) { //if the date is greater than or equal to "2021-01-01" add it to the new array
$newTimesArray[]=$date;
}
}
//print the results
echo print_r($newTimesArray,true);
?>