array_shift takes only unique code example

Example 1: remove first element in array php

$arr = [1,2,3,4];
array_shift($arr);
print_r($arr); // [2,3,4]

Example 2: array shift php

array_shift — Shift an element off the beginning of array
  
array_shift($array) shifts the first value of the array off and returns it,
shortening the array by one element and moving everything down. All numerical
array keys will be modified to start counting from zero while literal keys 
won't be affected.