Method ToLookup
ToLookup<TKey, TValue>(IEnumerable<KeyValuePair<TKey, TValue>>)
Creates an ILookup<TKey, TElement> from a sequence of KeyValuePair<TKey, TValue> elements.
Declaration
public static ILookup<TKey, TValue> ToLookup<TKey, TValue>(this IEnumerable<KeyValuePair<TKey, TValue>> source)Parameters
| Type | Name | Description |
|---|---|---|
| IEnumerable<KeyValuePair<TKey, TValue>> | source | The source sequence of key-value pairs. |
Returns
| Type | Description |
|---|---|
| ILookup<TKey, TValue> | An ILookup<TKey, TElement> containing the values mapped to their keys. |
Type Parameters
| Name | Description |
|---|---|
| TKey | The type of the key. |
| TValue | The type of the value. |
Remarks
This method executes immediately.
Exceptions
| Type | Condition |
|---|---|
| ArgumentNullException |
|
ToLookup<TKey, TValue>(IEnumerable<KeyValuePair<TKey, TValue>>, IEqualityComparer<TKey>?)
Creates an ILookup<TKey, TElement> from a sequence of KeyValuePair<TKey, TValue> elements. An additional parameter specifies a comparer for keys.
Declaration
public static ILookup<TKey, TValue> ToLookup<TKey, TValue>(this IEnumerable<KeyValuePair<TKey, TValue>> source, IEqualityComparer<TKey>? comparer)Parameters
| Type | Name | Description |
|---|---|---|
| IEnumerable<KeyValuePair<TKey, TValue>> | source | The source sequence of key-value pairs. |
| IEqualityComparer<TKey> | comparer | The comparer for keys. |
Returns
| Type | Description |
|---|---|
| ILookup<TKey, TValue> | An ILookup<TKey, TElement> containing the values mapped to their keys. |
Type Parameters
| Name | Description |
|---|---|
| TKey | The type of the key. |
| TValue | The type of the value. |
Remarks
This method executes immediately.
Exceptions
| Type | Condition |
|---|---|
| ArgumentNullException |
|
ToLookup<TKey, TValue>(IEnumerable<(TKey Key, TValue Value)>)
Creates an ILookup<TKey, TElement> /> from a sequence of tuples of 2 where the first item is the key and the second the value.
Declaration
public static ILookup<TKey, TValue> ToLookup<TKey, TValue>(this IEnumerable<(TKey Key, TValue Value)> source)Parameters
| Type | Name | Description |
|---|---|---|
| IEnumerable<(TKey Key, TValue Value)> | source | The source sequence of tuples of 2. |
Returns
| Type | Description |
|---|---|
| ILookup<TKey, TValue> | An ILookup<TKey, TElement> containing the values mapped to their keys. |
Type Parameters
| Name | Description |
|---|---|
| TKey | The type of the key. |
| TValue | The type of the value. |
Remarks
This method executes immediately.
Exceptions
| Type | Condition |
|---|---|
| ArgumentNullException |
|
ToLookup<TKey, TValue>(IEnumerable<(TKey Key, TValue Value)>, IEqualityComparer<TKey>?)
Creates an ILookup<TKey, TElement> from a sequence of tuples of 2 where the first item is the key and the second the value. An additional parameter specifies a comparer for keys.
Declaration
public static ILookup<TKey, TValue> ToLookup<TKey, TValue>(this IEnumerable<(TKey Key, TValue Value)> source, IEqualityComparer<TKey>? comparer)Parameters
| Type | Name | Description |
|---|---|---|
| IEnumerable<(TKey Key, TValue Value)> | source | The source sequence of tuples of 2. |
| IEqualityComparer<TKey> | comparer | The comparer for keys. |
Returns
| Type | Description |
|---|---|
| ILookup<TKey, TValue> | An ILookup<TKey, TElement> containing the values mapped to their keys. |
Type Parameters
| Name | Description |
|---|---|
| TKey | The type of the key. |
| TValue | The type of the value. |
Remarks
This method executes immediately.
Exceptions
| Type | Condition |
|---|---|
| ArgumentNullException |
|