Can not do the array equation in php - php

Question

I am trying to create an array equation where the array value will be equated to the existing sequence, but I can not display it in array..how do I fix it?
$ht = array('day' => 1,'day' =>2,'day' =>3,'day' =>4);
for ($x = 1; $x <= 10; $x++) {
if($x == $ht['day']){
echo 'x';
}else{
echo $x;
}
}
Which I expect xxxx5678910 but I result 123x45678910

Answer 1

This is your array :
$ht = array('day' => 1,'day' =>2,'day' =>3,'day' =>4);
I you just do var_dump($ht); you will see that you have :
array (size=1)
'day' => int 4
So try this to get what you want :
$ht = array(1 => 1, 2 => 2, 3 => 3, 4 => 4);
for ($x = 1; $x <= 10; $x++) {
if(!empty($ht[$x])){
echo 'x';
}else{
echo $x;
}
}
Output is : xxxx5678910
You have multiple way to achieve it, that's just one among other :)

Answer 2

When u use same key, u overwrite your array key, so at the and u have only one record in your array, u can try something like this:
<?php
$ht = array('day1' => 1,'day2' =>2,'day3' =>3,'day4' =>4);
var_dump($ht);
for ($x = 1; $x <= 10; $x++) {
if (isset($ht['day' . $x])) {
if($ht['day' . $x] == $x){
echo 'x';
}
} else{
echo $x;
}
}
?>
Return :
xxxx5678910

Answer 3

You don't need to loop at all to get the expected output.
You can use range() to create an array with numbers 1 to 10 as in the loop.
Then array_diff finds the numbers not in the $ht array so that they can be echoed with implode.
$ht = array(1 => 1, 2 => 2, 3 => 3, 4 => 4);
$range = range(1,10);
$diff = array_diff($range, $ht); // [5,6,7,8,9,10]
echo str_repeat("x", count($ht)) . implode("", $diff);
https://3v4l.org/ZCU15
If the numbers are not always consecutive you can use array_intersect, array_fill and array_flip to create the new array with "x" instead of numbers in $ht array.
Then use array_replace to replace number values with "x" and output with implode.
$ht = array(1 => 1, 2 => 2, 3 => 3, 4 => 9);
$range = range(0,10);
unset($range[0]); // unset 0 since you want 1 as lowest
$x = array_intersect_key(array_fill(1,max($ht), "x"), array_flip($ht));
// $x = [1=>"x", 2=>"x", 3 => "x", 9=>"x"]
$new = array_replace($range, $x);
echo implode("", $new);
https://3v4l.org/gtSl9