# list.select()

The `list.select()` function returns the list with elements selected by comparison consisting of `$operand`, `$operator`, `$value`, and `$values...`.

{% code lineNumbers="true" %}

```scss
// Sass.
@use 'sass:list';
@use 'sass:map';
@use 'sass:meta';

// Functions.
@use '../comparison/comparison.compare.function';
@use 'list.append.function' as *;
@use 'list.empty.function' as *;
@use 'list.first.function' as *;
@use 'list.index.function' as *;
@use 'list.nth.function' as *;
@use 'remove/remove.duplicate.function' as *;

// The `list.select()` function.
@function select(
  $select: index,
  $from: null,
  $operand: value,
  $operator: '==',
  $value,
  $values...
) {
  $result: ();
  $select: if(list.length($select) == 1, any $select, $select);
  $occurrence: list.nth(
    $select,
    index($select, all, any, end, first, last, only, start)
  );
  $select: list.nth($select, index($select, has, index, type, value));
  @each $value in append((), $value, comma, $values...) {
    $do: true;
    $compared-result: ();
    $index: 1;
    @while $do == true {
      $comparison-result: comparison.compare(
        map.get(
          (
            index: $index,
            type: meta.type-of(list.nth($from, $index)),
            value: list.nth($from, $index),
          ),
          $operand
        ),
        $operator,
        $value
      );

      @if $comparison-result or ($select == has and $occurrence == only) {
        $compared-result: list.append(
          $compared-result,
          map.get(
            (
              has: $comparison-result,
              index: $index,
              type: meta.type-of(list.nth($from, $index)),
              value: list.nth($from, $index),
            ),
            $select
          ),
          comma
        );
      }

      // Break the while.
      $do: if(
        $index ==
          list.length($from) or
          (
            not empty($compared-result) and list.index(first start, $occurrence)
          ),
        false,
        $do
      );
      $index: $index + 1;
    }

    $compared-result: if(empty($compared-result), null, $compared-result);

    @if $compared-result {
      @if $select == has and list.index(all only, $occurrence) {
        $compared-result: duplicate($compared-result);
        $compared-result: if(
          list.index($compared-result, null) or
            list.index($compared-result, false),
          false,
          true
        );
      }

      $compared-result: if(
        list.index(any first start end last, $occurrence),
        list.nth(
          $compared-result,
          if(
            list.index(any first start, $occurrence),
            1,
            list.length($compared-result)
          )
        ),
        if(
          list.length($compared-result) == 1,
          first($compared-result),
          $compared-result
        )
      );
    }

    $result: list.append($result, $compared-result, comma);
  }

  // has
  @if $select == has {
    $result: if(
      list.index(all, $occurrence),
      if(list.index($result, null) or list.index($result, false), false, true),
      if(
        list.index(any, $occurrence),
        if(list.index($result, true), true, false),
        if($occurrence == only, $result, false)
      )
    );
  }

  @return if(
    list.length($result) > 0,
    if(
      list.length($result) == 1 and not (type-of(nth($result, 1)) == list),
      first($result),
      $result
    ),
    null
  );
}

```

{% endcode %}

{% embed url="<https://github.com/angular-package/sass/blob/main/list/_list.select.function.scss>" %}

### Parameters

#### **`$select`**

The value of `list` or `string` type indicates what to retrieve from the given [`$from`](#usdfrom) list.

The value of `list` type consists of occurrence and selection, in order (occurrence selection). It's changed to (selection occurrence) when selection `has` is used, and there are `has only`, `has any`, `has all`. Occurrence (`all`, `any`, `end`, `first`, `last`, `only`) indicates how often compared elements occur in the given [`$from`](#usdfrom) list. Selection can take the values `has`, `index`, `type`, `value` and indicates what to retrieve from the list.

#### **`$from`**&#x20;

The list to retrieve elements from, by the given comparison.

#### `$operand`

The value of `string` type can take (index, type, value) and indicates an operand from the list used in the comparison.

|       |                     |
| ----- | ------------------- |
| index | element's index     |
| type  | type of the element |
| value | element's value     |

#### `$operator`

The operator used to compare [`$value`](#usdvalue) and/or [`$values`](#usdvalues...) with [`$operand`](#usdoperand) of the [`$from`](#usdfrom) list.

|     |                                                 |
| --- | ----------------------------------------------- |
| !   | not                                             |
| :   | type of                                         |
| (,) | list length                                     |
| (:) | map length                                      |
| === | compatbile or comparable                        |
| ==  | equal to                                        |
| \~= | text contains the given string (string.index()) |
| >   | greater than                                    |
| >=  | greater or equal than                           |
| <   | less than                                       |
| <=  | less or equal than                              |

#### `$value`

The required value to select from the given [`$from`](#usdfrom) list.

#### `$values...`

Additional values to select from the given [`$from`](#usdfrom) list.

### Return

The return value is the list with the elements selected by the given comparison.

## Examples

```scss
// Use.
@use 'angular-package/sass/list';

// Examples.


```


---

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