PHP Notice Undefined offset 1 with array when reading data

Question

I am getting this error :

PHP Notice:  Undefined offset: 1

This is the code that return the error:

$file_handle = fopen($path."/Summary/data.txt","r"); //open text file
$data = array(); // create new array map

while (!feof($file_handle) ) {
    $line_of_text = fgets($file_handle); // read in each line
    $parts = array_map('trim', explode(':', $line_of_text, 2)); 
    // separates line_of_text by ':' trim strings for extra space
    $data[$parts[0]] = $parts[1]; 
    // map the resulting parts into array 
    //$results('NAME_BEFORE_:') = VALUE_AFTER_:
}

 What causes this error? And what does this error mean?

Answer 1

It's a simple solution just change this:

$data[$parts[0]] = $parts[1];

To this:

if ( ! isset($parts[1])) {
   $parts[1] = null;
}

$data[$parts[0]] = $parts[1];

Or there is one more simple way that is:

$data[$parts[0]] = isset($parts[1]) ? $parts[1] : null;

I hope this helps you.