array_first

array_first

description

Returns the first element in the array for which func(arr1[i]) returns something other than 0.

Syntax

  1. T array_first(lambda, ARRAY<T>)

Use a lambda bool expression and an array as the input parameters, the lambda expression is used to evaluate the internal data of other input ARRAY parameters.

example

  1. mysql> select array_first(x->x>2, [1,2,3,0]) ;
  2. +------------------------------------------------------------------------------------------------+
  3. | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x(0) > 2, ARRAY(1, 2, 3, 0))), -1) |
  4. +------------------------------------------------------------------------------------------------+
  5. |                                                                                              3 |
  6. +------------------------------------------------------------------------------------------------+
  9. mysql> select array_first(x->x>4, [1,2,3,0]) ; 
  10. +------------------------------------------------------------------------------------------------+
  11. | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x(0) > 4, ARRAY(1, 2, 3, 0))), -1) |
  12. +------------------------------------------------------------------------------------------------+
  13. |                                                                                           NULL |
  14. +------------------------------------------------------------------------------------------------+
  17. mysql> select array_first(x->x>1, [1,2,3,0]) ;
  18. +---------------------------------------------------------------------------------------------+
  19. | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x > 1, ARRAY(1, 2, 3, 0))), 1) |
  20. +---------------------------------------------------------------------------------------------+
  21. |                                                                                           2 |
  22. +---------------------------------------------------------------------------------------------+

keywords

ARRAY, LAST, array_first