privatenew arrgh.Lookup(source, keySelector, elementSelector, eqComparer)
Represents a collection of keys each mapped to one or more values.
| Name | Type | Default | Description |
|---|---|---|---|
source |
arrgh.Enumerable | The collection to map to a lookup. | |
keySelector |
keySelector | A function that returns the key value from an element of the inner collection. | |
elementSelector |
selector | optional A function that projects an element into a new form. | |
eqComparer |
equalityComparer | (===) | optional An object that tests if two keys are equal. |
Extends
Methods
-
inherited aggregate(seed, accumulator, resultSelector){*}
-
Determines whether all elements of the collection satisfy a condition.
When a result selector is passed to the function a seed should also be specified.Name Type Description seed* optional The initial accumulator value (mandatory if a result selector is specified). accumulatoraccumulator An accumulator function to be invoked on each element. resultSelectorselector optional A function to transform the final accumulator value into the result value. Returns:
Type Description * - The final accumulator value. -
inherited all(predicate){Boolean}
-
Determines whether all elements of the collection satisfy a condition.
Name Type Description predicatepredicate A function to test each element for a condition. Returns:
Type Description Boolean - True if the list is empty or if all elements in the collection satisfy a condition, else false. -
inherited any(predicate){Boolean}
-
Determines whether the collection contains any elements or if any elements satisfy a condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. Returns:
Type Description Boolean - True if the collection contains any elements or if any elements satisfy a condition, else false. -
inherited asEnumerable(){arrgh.Enumerable}
-
Returns the input typed as Enumerable.
Returns:
Type Description arrgh.Enumerable - The input collection as Enumerable. -
inherited average(selector){Number}
-
Computes the average of a collection of values.
Values are converted to numerics, but if this fails unexpected averages may occur.Name Type Description selectorselector optional A function that projects an element into a new form. Throws:
Throws an error if the collection contains no elements.Returns:
Type Description Number - The average of all values in the collection, or NaN. -
inherited concat(other){arrgh.Enumerable}
-
Concatenates two collections.
Name Type Description otherother The collection to concatenate to the current collection. Returns:
Type Description arrgh.Enumerable - A collection that contains all the elements of both the current and the other collection. -
inherited contains(elem, eqComparer){Boolean}
-
Determines whether a collection contains a specified element, optionally uses a custom equality comparer.
Name Type Default Description elem* The element to locate in the collection. eqComparerequals | equalityComparer (===) optional A function or object that tests if two elements are equal. Returns:
Type Description Boolean - Returns whether the specified element is contained in the collection. -
inherited count(predicate){Number}
-
Specifies how many elements the collection has, or how many satisfy a certain condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. Returns:
Type Description Number - A number that specifies how many elements the collection has, or how many satisfy a certain condition. -
inherited defaultIfEmpty(defaultValue){arrgh.Enumerable}
-
Returns the elements of the specified collection or a collection containing only the default value if the collection is empty.
Name Type Description defaultValue* The default value to be returned when the collection is empty. Returns:
Type Description arrgh.Enumerable - A new collection containing the elements of the specified collection or a new collection containing only the default value if the collection is empty. -
inherited distinct(eqComparer){arrgh.Enumerable}
-
Returns distinct elements from a collection by using the default or a custom equality comparer to compare values.
Name Type Default Description eqComparerequals | equalityComparer (===) optional A function or object that tests if two elements are equal. Returns:
Type Description arrgh.Enumerable - A new collection with unique elements. -
inherited elementAt(index){*}
-
Returns the element at a specified index.
Name Type Description indexNumber The index of the element to find. Throws:
Throws an error if the specified index is outside the bounds of the collection.Returns:
Type Description * - The element at the specified index. -
inherited elementAtOrDefault(index, defaultValue){*}
-
Returns the element at a specified index or a default value.
Name Type Description indexNumber The index of the element to find. defaultValue* optional The value that is returned when the specified index is not found. Returns:
Type Description * - The element at the specified index or a default value. -
inherited except(other, eqComparer){arrgh.Enumerable}
-
Produces the set difference of two collections.
Name Type Default Description otherarrgh.Enumerable A collection whose elements that also occur in the first sequence will cause those elements to be removed from the returned collection. eqComparerequals | equalityComparer (===) optional A function or object that tests if two elements are equal. Returns:
Type Description arrgh.Enumerable - A collection that contains the set difference of the elements of two collections. -
inherited filter(predicate){arrgh.Enumerable}
-
Filters a collection of values based on a predicate. Each element's index is used in the logic of the predicate function.
Name Type Description predicateindexPredicate A function to test each element for a condition. Returns:
Type Description arrgh.Enumerable - A collection that contains all elements that satisfy the condition. -
inherited first(predicate){*}
-
Returns the first element in a collection, or the first element that satisfies a condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. Throws:
Throws an error if the collection is empty or when no element matches the condition.Returns:
Type Description * - Returns the first element of the collection, or the first element that satisfies a condition. -
inherited firstOrDefault(predicate, defaultValue){*}
-
Returns the first element in a collection, or the first element that satisfies a condition.
If the element is not found returns a default value.Name Type Description predicatepredicate optional A function to test each element for a condition. defaultValue* optional The value that is returned when the collection is empty or no element matches the condition. Returns:
Type Description * - Returns the first element of the collection, or the first element that satisfies a condition, or a specified default value. -
inherited forEach(callback)
-
Performs the specified action on each element of the collection.
Name Type Description callbackforEachCallback The callback that is applied to each element in the enumerable. -
get(key){grouping}
-
Gets the collection at the specified key.
Name Type Description key* The key of the collection which should be retrieved. Returns:
Type Description grouping - Returns the collection with the specified key or an empty collection if the key was not found. -
inherited getIterator(){arrgh.Iterator}
-
Returns an iterator that iterates through the collection.
Returns:
Type Description arrgh.Iterator - Returns an iterator that iterates through the collection. -
inherited groupBy(keySelector, elementSelector, resultSelector, eqComparer)
-
Groups the elements of a collection according to a specified key selector.
Name Type Default Description keySelectorkeySelector A function that returns the key value from an element. elementSelectorselector optional A function to project an element into a new form. resultSelectorgroupByResultSelector optional A function to create a result value from each group. eqComparerequalityComparer (===) optional An object that tests if two keys are equal. -
inherited groupJoin(inner, outerKeySelector, innerKeySelector, resultSelector, eqComparer){arrgh.Enumerable}
-
Correlates the elements of two collections based on equality of keys and groups the results.
Name Type Default Description innerarrgh.Enumerable The collection to join with. outerKeySelectorkeySelector A function that returns the key value from an element of the outer collection. innerKeySelectorkeySelector A function that returns the key value from an element of the inner collection. resultSelectorgroupJoinResultSelector A function to create a result value from each group. eqComparerequalityComparer (===) optional An object that tests if two keys are equal. Returns:
Type Description arrgh.Enumerable - A collection that contains elements that are obtained by performing a grouped join on two collections. -
inherited indexOf(searchElem, fromIndex){Number}
-
Finds the first index at which a given element can be found in the collection, or -1 if it is not present.
Name Type Default Description searchElem* The element to locate in the collection. fromIndexNumber 0 optional The index to start the search at. Returns:
Type Description Number - The first index of the element in the array or -1 if not found. -
inherited intersect(other, eqComparer){arrgh.Enumerable}
-
Produces the set intersection of two collections.
Name Type Default Description otherarrgh.Enumerable A collection whose elements that also occur in the first sequence will cause those elements to be included in the returned collection. eqComparerequals | equalityComparer (===) optional A function or object that tests if two elements are equal. Returns:
Type Description arrgh.Enumerable - A collection that contains the set intersection of the elements of two collections. -
inherited join(inner, outerKeySelector, innerKeySelector, resultSelector, eqComparer)
-
Correlates the elements of two collections based on equality of keys.
Name Type Default Description innerarrgh.Enumerable The collection to join with. outerKeySelectorkeySelector A function that returns the key value from an element of the outer collection. innerKeySelectorkeySelector A function that returns the key value from an element of the inner collection. resultSelectorjoinResultSelector A function to create a result from two matched elements. eqComparerequalityComparer (===) optional An object that tests if two keys are equal. -
inherited last(predicate){*}
-
Returns the last element in a collection, or the last element that satisfies a condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. Throws:
Throws an error when the collection is empty or when no element matches the condition.Returns:
Type Description * - Returns the last element of the collection, or the last element that satisfies a condition. -
inherited lastIndexOf(searchElem, fromIndex){Number}
-
Finds the last index at which a given element can be found in the collection, or -1 if it is not present.
Name Type Default Description searchElem* The element to locate in the collection. fromIndexNumber 0 optional The index to start the search at. Returns:
Type Description Number - The last index of the element in the array or -1 if not found. -
inherited lastOrDefault(predicate, defaultValue){*}
-
Returns the last element in a collection, or the last element that satisfies a condition.
If the element is not found returns a default value.Name Type Description predicatepredicate optional A function to test each element for a condition. defaultValue* optional The value that is returned when the collection is empty or no element matches the condition. Returns:
Type Description * - Returns the last element of the collection, or the last element that satisfies a condition, or a specified default value. -
inherited map(selector){arrgh.Enumerable}
-
Projects each element of a collection into a new form.
Name Type Description selectorindexSelector A function that projects an element into a new form. Returns:
Type Description arrgh.Enumerable - A collection whose elements are the result of invoking the transform function on each element of source. -
inherited max(selector){*}
-
Returns the maximum value in a collection.
Values are converted to numerics. If this fails and the value is NaN then NaN is treated as smaller than anything.Name Type Description selectorselector optional A function that projects an element into a new form. Throws:
Throws an error when the collection is empty.Returns:
Type Description * - Returns the maximum value in the collection or NaN. -
inherited min(selector){*}
-
Returns the minimum value in a collection.
Values are converted to numerics. If this fails the function returns NaN.Name Type Description selectorselector optional A function that projects an element into a new form. Throws:
Throws an error when the collection is empty.Returns:
Type Description * - Returns the minimum value in the collection or NaN. -
inherited ofType(type){arrgh.Enumerable}
-
Filters elements based on a specified type (constructor).
Object and null do not evaluate to the same type and neither do undefined and null.Name Type Description type* | undefined | null The constructor of a type or undefined or null. Returns:
Type Description arrgh.Enumerable - Returns a collection containing only values that are of the specified type. -
inherited orderBy(keySelector, compare){arrgh.OrderedEnumerable}
-
Sorts the elements of a sequence in ascending order according to a key.
Name Type Description keySelectorkeySelector A function to extract a key from an element. comparecompare optional A function that tests if an object is smaller than, greater than or equal to another object. Returns:
Type Description arrgh.OrderedEnumerable - Returns an ordered enumerable. -
inherited orderByDescending(keySelector, compare){arrgh.OrderedEnumerable}
-
Sorts the elements of a sequence in descending order according to a key.
Name Type Description keySelectorkeySelector A function to extract a key from an element. comparecompare optional A function that tests if an object is smaller than, greater than or equal to another object. Returns:
Type Description arrgh.OrderedEnumerable - Returns an ordered enumerable. -
inherited reverse(){arrgh.Enumerable}
-
Reverses the order of the elements in a collection.
Returns:
Type Description arrgh.Enumerable - A collection that contains the original collection in reversed order. -
inherited select(selector){arrgh.Enumerable}
-
Projects each element of a collection into a new form.
Name Type Description selectorindexSelector A function that projects an element into a new form. - See:
Returns:
Type Description arrgh.Enumerable - A collection whose elements are the result of invoking the transform function on each element of source. -
inherited selectMany(collectionSelector, resultSelector){arrgh.Enumerable}
-
Projects each element of a collection to an Enumerable and flattens the resulting collections into one collection.
Name Type Description collectionSelectorcollectionSelector A function that projects an element into a new form. resultSelectorselectManyResultSelector optional A function that creates a result value from each element in the intermediate collection. Returns:
Type Description arrgh.Enumerable - A collection whose elements are the result of invoking the one-to-many transform function on each element of the input collection. -
inherited sequenceEquals(other, eqComparer){Boolean}
-
Determines whether two collections are equal by comparing the elements, optionally using a custom equality comparer for their type.
Name Type Default Description otherarrgh.Enumerable Another collection to compare with. eqComparerequalityComparer (===) optional An object that tests if two objects are equal. Returns:
Type Description Boolean - True if all elements in both collections match, otherwise false. -
inherited single(predicate){*}
-
Returns the only element in a collection, or the only element that satisfies a condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. Throws:
Throws an error when the collection is empty or when no element matches the condition or when the collection (or predicate) returns more than a single element.Returns:
Type Description * - Returns the only element of the collection, or the only element that satisfies a condition. -
inherited singleOrDefault(predicate, defaultValue){*}
-
Returns the only element in a collection, or the only element that satisfies a condition.
If the element is not found returns a default value.Name Type Description predicatepredicate optional A function to test each element for a condition. defaultValue* optional The value that is returned when the collection is empty or no element matches the condition. Throws:
Throws an error when the collection (or predicate) returns more than a single element.Returns:
Type Description * - Returns the only element of the collection, or the only element that satisfies a condition, or a specified default value. -
inherited skip(count){arrgh.Enumerable}
-
Bypasses a specified number of elements in a collection and then returns the remaining elements.
Name Type Description countNumber The number of elements to skip. Returns:
Type Description arrgh.Enumerable - A collection that contains the elements that occur after the specified index. -
inherited skipWhile(predicate){arrgh.Enumerable}
-
Bypasses elements in a collection as long as a specified condition is true and then returns the remaining elements.
Name Type Description predicateindexPredicate A function to test whether to skip the element. Returns:
Type Description arrgh.Enumerable - A collection that contains the elements starting at the first element in the linear series that does not pass the test specified by predicate. -
inherited some(predicate){Boolean}
-
Determines whether the collection contains any elements or if any elements satisfy a condition.
Name Type Description predicatepredicate optional A function to test each element for a condition. - See:
Returns:
Type Description Boolean - True if the collection contains any elements or if any elements satisfy a condition, else false. -
inherited sum(selector){Number}
-
Computes the sum of a collection of values.
If values are not numerics the result may be NaN or something unexpected (e.g. "2" + 2 will results 22).Name Type Description selectorselector optional A function that projects an element into a new form. Throws:
Throws an error if the collection contains no elements.Returns:
Type Description Number - The sum of all values in the collection, or NaN. -
inherited take(count){arrgh.Enumerable}
-
Returns a specified number of elements from the start of a collection.
Name Type Description countNumber The number of elements to take. Returns:
Type Description arrgh.Enumerable - A collection that contains the elements that occur before the specified index. -
inherited takeWhile(predicate){arrgh.Enumerable}
-
Returns elements from a collection as long as a specified condition is true.
Name Type Description predicateindexPredicate A function to test whether to take the element. Returns:
Type Description arrgh.Enumerable - A collection that contains the elements that occur before the element at which the test no longer passes. -
inherited toArray(){Array}
-
Converts the collection to a JavaScript array.
Returns:
Type Description Array - Returns a JavaScript array. -
inherited toDictionary(keySelector, elementSelector, eqComparer){arrgh.Dictionary}
-
Converts the collection to a dictionary.
Name Type Default Description keySelectorkeySelector A function that returns the key value from an element of the inner collection. elementSelectorselector optional A function that projects an element into a new form. eqComparerequalityComparer (===) optional An object that tests if two keys are equal. Returns:
Type Description arrgh.Dictionary - Returns a dictionary containing the keys and elements that are selected from the input collection. -
inherited toList(){arrgh.List}
-
Converts the collection to a list.
Returns:
Type Description arrgh.List - Returns a List containing all the elements from the input collection. -
inherited toLookup(keySelector, elementSelector, eqComparer){arrgh.Lookup}
-
Converts the collection to a collection of keys each mapped to one or more values.
Name Type Default Description keySelectorkeySelector A function that returns the key value from an element of the inner collection. elementSelectorselector optional A function that projects an element into a new form. eqComparerequalityComparer (===) optional An object that tests if two keys are equal. Returns:
Type Description arrgh.Lookup - Returns a collection of keys mapped to one or more values. -
inherited union(other, eqComparer){arrgh.Enumerable}
-
Produces the set union of two collections by using the default or a custom equality comparer to compare values.
Name Type Default Description otherarrgh.Enumerable The other collection to union with. eqComparerequalityComparer (===) optional An object that tests if two elements are equal. Returns:
Type Description arrgh.Enumerable - A collection that contains distinct element from the two input collections. -
inherited unionAll(other){arrgh.Enumerable}
-
Concatenates two collections.
Name Type Description otherother The collection to concatenate to the current collection. Returns:
Type Description arrgh.Enumerable - A collection that contains all the elements of both the current and the other collection. -
inherited where(predicate){arrgh.Enumerable}
-
Filters a collection of values based on a predicate. Each element's index is used in the logic of the predicate function.
Name Type Description predicateindexPredicate A function to test each element for a condition. Returns:
Type Description arrgh.Enumerable - A collection that contains all elements that satisfy the condition. -
inherited zip(other, resultSelector){arrgh.Enumerable}
-
Applies a specified function to the corresponding elements of two collections, producing a collection of the results.
Name Type Description otherarrgh.Enumerable The collection to merge with. resultSelectorzipResultSelector A function that creates a result value from two elements. Returns:
Type Description arrgh.Enumerable - A collection that contains merged elements of two input collections.