Converting array elements into range in php

Question

I’m working on an array of numeric values.

I have a array of numeric values as the following in PHP

11,12,15,16,17,18,22,23,24

And

Answer 1

The answer provided by Ali Gajani kept giving me "Illegal offset" warnings. So, because I figured somebody might want to use it as badly as I do, I'm posting my fixes here - though note that my fixes might be deemed silly by an advanced programmer - it does seem to work now with no issues.

I replaced/tweaked two parts of the code. Below you will see what I added (marked in bold) and what was removed, which I commented (//).

As near as I can tell, it was having trouble on the first pass because there was no "previous pass" to refer to (hence, it was balking at "$previous = $array[$i-1];") - and on the last pass for a similar reason. In that second instance, I simply moved "$next_key = $break_start[$i+1];" below the last iteration check.

$break_start = array();

//range finder
for ($i=0; $i0) {
        $previous = $array[$i-1];
}
else {
        $previous = $current;
}**
  //  $previous = $array[$i-1];
    if ($current==($previous+1)) { 
        //no break points are found 
    } else { 
        //return break points with keys intact
        array_push($break_start, $i);
    }

}

for ($i=0; $i

If there are smarter ways to get this done, please advise. But I searched high and low for this - and figured someone else might also benefit. Another tip of the hat to Ali Gajani for his initial help.