| --- |
| { |
| "title": "ARRAY_FIRST", |
| "language": "en" |
| } |
| --- |
| |
| ## array_first |
| |
| array_first |
| |
| ### description |
| Returns the first element in the array for which func(arr1[i]) returns something other than 0. |
| |
| #### Syntax |
| |
| ``` |
| 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 |
| |
| ``` |
| mysql> select array_first(x->x>2, [1,2,3,0]) ; |
| +------------------------------------------------------------------------------------------------+ |
| | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x(0) > 2, ARRAY(1, 2, 3, 0))), -1) | |
| +------------------------------------------------------------------------------------------------+ |
| | 3 | |
| +------------------------------------------------------------------------------------------------+ |
| |
| |
| mysql> select array_first(x->x>4, [1,2,3,0]) ; |
| +------------------------------------------------------------------------------------------------+ |
| | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x(0) > 4, ARRAY(1, 2, 3, 0))), -1) | |
| +------------------------------------------------------------------------------------------------+ |
| | NULL | |
| +------------------------------------------------------------------------------------------------+ |
| |
| |
| mysql> select array_first(x->x>1, [1,2,3,0]) ; |
| +---------------------------------------------------------------------------------------------+ |
| | array_first(array_filter(ARRAY(1, 2, 3, 0), array_map([x] -> x > 1, ARRAY(1, 2, 3, 0))), 1) | |
| +---------------------------------------------------------------------------------------------+ |
| | 2 | |
| +---------------------------------------------------------------------------------------------+ |
| ``` |
| |
| |
| ### keywords |
| |
| ARRAY, LAST, array_first |