> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/perl6-rosettacode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/perl6-rosettacode/programming_tasks/s/search_a_list_of_records.md).

# Search a list of records

The built-in method `.first` fulfills the requirements of this task.

It takes any [smart-matcher](https://docs.raku.org/language/operators#infix_~~) as a predicate. The `:k` adverb makes it return the key (i.e. numerical index) instead of the value of the element.

```perl
my @cities =
  { name => 'Lagos',                population => 21.0  },
  { name => 'Cairo',                population => 15.2  },
  { name => 'Kinshasa-Brazzaville', population => 11.3  },
  { name => 'Greater Johannesburg', population =>  7.55 },
  { name => 'Mogadishu',            population =>  5.85 },
  { name => 'Khartoum-Omdurman',    population =>  4.98 },
  { name => 'Dar Es Salaam',        population =>  4.7  },
  { name => 'Alexandria',           population =>  4.58 },
  { name => 'Abidjan',              population =>  4.4  },
  { name => 'Casablanca',           population =>  3.98 },
;

say @cities.first(*<name> eq 'Dar Es Salaam', :k);
say @cities.first(*<population> < 5).<name>;
say @cities.first(*<name>.match: /^A/).<population>;
```

#### Output:

```
6
Khartoum-Omdurman
4.58
```