C.Collection

What

Support method for collections

IsNullOrEmpty

bool IsNullOrEmpty<T>(this List<T>)
bool IsNullOrEmpty<T>(this T[])
bool IsNullOrEmpty<TKey, TValue>(this Dictionary<TKey, TValue>)

Check null or empty for list, array and dictionary

Example

private List<int> _list;

var flag = _list.IsNullOrEmpty();

Shuffle

void Shuffle<T>(this T[])
void Shuffle<T>(this List<T>)
IDictionary<T1, T2> Shuffle<T1, T2>(this IDictionary<T1, T2>)

Shuffle element in collections, For arrays and lists, it will be changed directly, while dictionary will return a new shuffled dictionary and not change to the original dictionary

Example

private List<int> _list = new {1, 2, 3, 4, 5};

_list.Shuffle();

MakeDictionary

IDictionary<TKey, TValue> MakeDictionary<TKey, TValue>(this TKey[] keys, TValue[] values)
IDictionary<TKey, TValue> MakeDictionary<TKey, TValue>(this IList<TKey> keys, IList<TValue> values)

make dictionay from list key and list value

Example

private List<int> keys = new {1, 2, 3, 4, 5};
private List<string> values = new {"a", "b", "c", "d", "e"};

keys.MakeDictionary(values);

PickRandom

T PickRandom<T>(this T[])
T PickRandom<T>(this List<T>)

Indicates the random value in the collections. If collections is empty return default vaule of T.

Return a random value of index within [0..maxExclusive) (Read Only)

maxExclusive = length of collections

maxExclusive is exclusive, so for example collections has 10 element will return a value of index between 0 and 9, each with approximately equal probability

If maxExclusive equal 0, value of index 0 will be returned.

Example

private List<int> keys = new {1, 2, 3, 4, 5};

var key = keys.PickRandom();

PickRandomWithIndex

(T, int) PickRandomWithIndex<T>(this T[])
(T, int) PickRandomWithIndex<T>(this List<T>)

Indicates the random value in the collections and index of value inside collection. If collections is empty return default vaule of T.

Return a random value of index within [0..maxExclusive) (Read Only)

maxExclusive = length of collections

maxExclusive is exclusive, so for example collections has 10 element will return a value of index between 0 and 9, each with approximately equal probability

If maxExclusive equal 0, value of index 0 will be returned.

Example

private List<int> keys = new {1, 2, 3, 4, 5};

(int key, int index) = keys.PickRandomWithIndex();

PopRandom

T PopRandom<T>(this List<T>)

Indicates the random value in the collections and also remove that element. If collections is empty return default vaule of T.

Return a random value of index within [0..maxExclusive) (Read Only)

maxExclusive = length of collections

maxExclusive is exclusive, so for example collections has 10 element will return a value of index between 0 and 9, each with approximately equal probability

If maxExclusive equal 0, value of index 0 will be returned.

Example

private List<int> keys = new {1, 2, 3, 4, 5};

var key = keys.PopRandom(); // keys will be only 4 elements left

PopRandomWithIndex

(T, int) PopRandomWithIndex<T>(this List<T>)

Indicates the random value in the collections and return index of element and also remove that element. If collections is empty return default vaule of T.

Return a random value of index within [0..maxExclusive) (Read Only)

maxExclusive = length of collections

maxExclusive is exclusive, so for example collections has 10 element will return a value of index between 0 and 9, each with approximately equal probability

If maxExclusive equal 0, value of index 0 will be returned.

Example

private List<int> keys = new {1, 2, 3, 4, 5};

(int key, int index) = keys.PopRandomWithIndex(); // keys will be only 4 elements left

Swap

void Swap<T>(this T[], int, int)
void Swap<T>(this List<T>, int, int)

swap element in array

Example

private List<int> keys = new {1, 2, 3, 4, 5};

keys.Swap(0, 1); // keys now look like {2, 1, 3, 4, 5}