Unset range of keys in an array

Question

How can I disable the key range from 70 to 80 in such an array?

[63] => Computer Science and Informatics [64] => Dentistry [65] => Development Studies [66] => Drama, Dance and Performing Arts [67] => Earth Systems and Environmental Sciences [68] => Economics and Econometrics [69] => Education [70] => Electrical and Electronic Engineering [71] => English Language and Literature [72] => Epidemiology and Public Health [73] => European Studies [74] => French [75] => General Engineering and Mineral & Mining Engineering [76] => Geography and Environmental Studies [77] => Geography and Environmental Studies [78] => German, Dutch and Scandinavian Languages [79] => Health Services Research [80] => History [81] => History of Art, Architecture and Design [82] => Iberian and Latin American Languages [83] => Infection and Immunology [84] => Italian [85] => Law [86] => Library and Information Management [87] => Linguistics [88] => Mechanical, Aeronautical and Manufacturing Engineering [89] => Metallurgy and Materials [90] => Middle Eastern and African Studies 

Answer 1

You can try array_slice

 $return = array_slice($original, 0, 60) 

then

 $return = $return+array_slice($original, 70) 

or

array_splice

 $return = array_splice($original, 60, 10) 

Answer 2

There is actually no shortcut for this:

 for ($i = 70; $i <= 80; $i++) unset($array[$i]);