Undefined offset error and undefined variable error even if defined - php

Question

I have a function that I am writing to take in values datetime values from an array and convert it into hours and minutes format like 0010. I want to use this to later extract other values from the array as this is an associative array
function getData($lengthArray, $csvdat) { # passing down the values of the array and the length of the array
$newData = array(
'nightTime1',
'nightTime2',
'dayTime1',
'peakTime',
'dayTime2',
'winterNightTime1',
'winterNightTime2',
'winterDayTime1',
'winterDayTime2',
'winterPeakTime');
for ($count = 0; $count <= $lengthArray; $count++ ) { #looping to the length of the array
$arrayTimestamp = $csvdat[$count]['timestamp'];
$comparator = date('Hs', strtotime($arrayTimestamp)); #extracting the time format
$nightTime1 = 0759;
$dayTime1 = 1659;
$peakTime = 1859;
$dayTime2 = 2259;
$nightTime2 = 2359;
if ( $comparator == $nightTime1 ) {
if (empty($newData['nightTime1'])) {
$newData['nightTime1'] = $nightTime;
$newData['nightTime1']['phase1'] = $csvdat[$count++]['day_chan1'];
$newData['nightTime1']['phase1'] = $csvdat[$count++]['day_chan2'];
$newData['nightTime1']['phase1'] = $csvdat[$count++]['day_chan3'];
}
else if (!empty($newData)) {
}
}
}
return $newData;
}
getData($lengthData , $csvdata);
var_dump($newData);
The problem I am facing now is that I get an Undefined offset error at the line
$arrayTimestamp = $csvdat[$count]['timestamp'];
and an undefined variable for $newData. I am not very good at php so please advise.
Here is the var_dump of the csvdat array
array (size=118061)
0 =>
array (size=15)
'timestamp' => string '01/02/2014 00:00' (length=16)
'curr_property' => string '5972' (length=4)
'curr_property_cost' => string '62' (length=2)
'day_property' => string '19' (length=2)
'day_property_cost' => string '0' (length=1)
'curr_solar_generating' => string '2898' (length=4)
'curr_solar_export' => string '0' (length=1)
'day_solar_generated' => string '9' (length=1)
'day_solar_export' => string '0' (length=1)
'curr_chan1' => string '2189' (length=4)
'curr_chan2' => string '2898' (length=4)
'curr_chan3' => string '885' (length=3)
'day_chan1' => string '7' (length=1)
'day_chan2' => string '9' (length=1)
'day_chan3' => string '2' (length=1)
1 =>
array (size=15)
'timestamp' => string '01/02/2014 00:00' (length=16)
'curr_property' => string '5215' (length=4)
'curr_property_cost' => string '54' (length=2)
'day_property' => string '37' (length=2)
'day_property_cost' => string '0' (length=1)
'curr_solar_generating' => string '2141' (length=4)
'curr_solar_export' => string '0' (length=1)
'day_solar_generated' => string '16' (length=2)
'day_solar_export' => string '0' (length=1)
'curr_chan1' => string '2173' (length=4)
'curr_chan2' => string '2141' (length=4)
'curr_chan3' => string '901' (length=3)
'day_chan1' => string '14' (length=2)
'day_chan2' => string '16' (length=2)
'day_chan3' => string '5' (length=1)
2 =>
array (size=15)
'timestamp' => string '01/02/2014 00:00' (length=16)
'curr_property' => string '5215' (length=4)
'curr_property_cost' => string '54' (length=2)
'day_property' => string '54' (length=2)
'day_property_cost' => string '0' (length=1)
'curr_solar_generating' => string '2157' (length=4)
'curr_solar_export' => string '0' (length=1)
'day_solar_generated' => string '23' (length=2)
'day_solar_export' => string '0' (length=1)
'curr_chan1' => string '2157' (length=4)
'curr_chan2' => string '2157' (length=4)
'curr_chan3' => string '901' (length=3)
'day_chan1' => string '21' (length=2)
'day_chan2' => string '23' (length=2)
'day_chan3' => string '8' (length=1)
3 =>
array (size=15)
'timestamp' => string '01/02/2014 00:00' (length=16)
'curr_property' => string '5183' (length=4)
'curr_property_cost' => string '54' (length=2)
'day_property' => string '71' (length=2)
'day_property_cost' => string '0' (length=1)
'curr_solar_generating' => string '2125' (length=4)
'curr_solar_export' => string '0' (length=1)
'day_solar_generated' => string '31' (length=2)
'day_solar_export' => string '0' (length=1)
'curr_chan1' => string '2173' (length=4)
'curr_chan2' => string '2125' (length=4)
'curr_chan3' => string '885' (length=3)
'day_chan1' => string '28' (length=2)
'day_chan2' => string '31' (length=2)
'day_chan3' => string '11' (length=2)

Answer 1

Try
for ($count = 0; $count < $lengthArray; $count++ )
instead of
for ($count = 0; $count <= $lengthArray; $count++ )

Answer 2

If and only if you are 100% sure that $lengthArray is the size of the $csvdat array, then your error is caused by this line:
for ($count = 0; $count <= $lengthArray; $count++ ) {
it should be
for ($count = 0; $count < $lengthArray; $count++ ) {
Right now you're breaking the loop if the $count is lower OR the same as $lengthArray. Notice that last key in your array is 3 and its length is 4.
EDIT
Now about Undefined variable: $newData.
You're trying to var_dump($newData) which is undefined. It exists inside the getData function but not outside it. Maybe you wanted to do it like this:
$newData = getData($lengthData , $csvdata);
var_dump($newData);

Answer 3

It should be $count < $lengthArray in for loop
for ($count = 0; $count < $lengthArray; $count++ ) {
}