sorting array without php built-in sort function - php

Question

I am very newbie on programming, first studying PHP language about arrays. I can sort an array with sort function, but I got stuck here.
If i have input array(1,3,5,6,7,8,11,12,17,11)
I try to get output 12 or bigger number 2, but if I do print_r($array[i] - 1);
I just get 10-1=9. how can i get value 12?
and then if I have input array(1,2,3,5,6) I try to get output false because of the missing number 4.
I make sort function:
for(int j:0;j<=count($array) ;j++) {
for(int i:0;i<=count($array[i+1]);i++{
if($array[i]>$array[$+1]{
$temp=$array[$i+1];
$array[$i+1]=$array[$i];
$array[$i]=temp;
}
}
}
print_r($array) ;
Thanks if someone can help me or teach me? :)

Answer 1

You have a lot of syntax errors in your code. Check the comments under your question, they pretty much covered it.
To sort an array with a custom sort you can use this:
$array = array(1,3,5,6,7,8,11,12,17,11);
$arrayCount = count($array); // no need to evaluate the count on every iteration of the for loop
for($i=0; $i < $arrayCount - 1; $i++)
{
for($j = $i+1; $j < $arrayCount; $j++)
{
// if you want the array sorted from bigger to smaller number use `>` here
if($array[$j] < $array[$i])
{
$temp = $array[$i];
$array[$i] = $array[$j];
$array[$j] = $temp;
}
}
}
print_r($array);
which outputs:
Array
(
[0] => 1
[1] => 3
[2] => 5
[3] => 6
[4] => 7
[5] => 8
[6] => 11
[7] => 11
[8] => 12
[9] => 17
)
Now to retrieve a desired value from the array or false if it does not exist you would write something like this using the built in array_search() method:
// Check if array contains a value 12, if it does return the index location in the array
// returns false if the value is not found
$index = array_search(12, $array);
if($index === false)
{
echo 'Value does not exist in the array.';
}
else
{
echo 'Value '.$array[$index].' is at index '.$index.' in the array.';
}