Collection Functions (Arrays or Objects)
_.each(list, iterator, [context]) Alias: forEach Iterates over a list of elements, yielding each in turn to an iterator function. The iterator is bound to the
_.map(list, iterator, [context]) Alias: collect Produces a new array of values by mapping each value in list through a transformation function (
_.reduce(list, iterator, memo, [context]) Aliases: inject, foldl Also known as inject and foldl, reduce boils down a list of values into a single value.
_.reduceRight(list, iterator, memo, [context]) Alias: foldr The right-associative version of reduce. Delegates to the JavaScript 1.8 version of
_.find(list, iterator, [context]) Alias: detect Looks through each value in the list, returning the first one that passes a truth test (iterator). The function returns as
_.filter(list, iterator, [context]) Alias: select Looks through each value in the list, returning an array of all the values that pass a truth test (
_.where(list, properties) Looks through each value in the list, returning an array of all the values that contain all of the key-value pairs listed in
_.findWhere(list, properties) Looks through the list and returns the first value that matches all of the key-value pairs listed in properties.
_.reject(list, iterator, [context]) Returns the values in list without the elements that the truth test (iterator) passes. The opposite of filter.
_.every(list, iterator, [context]) Alias: all Returns true if all of the values in the list pass the iterator truth test. Delegates to the native method
_.some(list, [iterator], [context]) Alias: any Returns true if any of the values in the list pass the iterator truth test. Short-circuits and stops traversing the list
_.contains(list, value) Alias: include Returns true if the value is present in the list. Uses indexOf internally, if list is an Array.
_.invoke(list, methodName, [*arguments]) Calls the method named by methodName on each value in the list. Any extra arguments passed to
_.pluck(list, propertyName) A convenient version of what is perhaps the most common use-case for map: extracting a list of property values.
_.max(list, [iterator], [context]) Returns the maximum value in list. If iterator is passed, it will be used on each value to generate the criterion by which the
_.min(list, [iterator], [context]) Returns the minimum value in list. If iterator is passed, it will be used on each value to generate the criterion by which the
_.sortBy(list, iterator, [context]) Returns a sorted copy of list, ranked in ascending order by the results of running each value through iterator
_.groupBy(list, iterator, [context]) Splits a collection into sets, grouped by the result of running each value through iterator. If iterator is a string instead of
_.countBy(list, iterator, [context]) Sorts a list into groups and returns a count for the number of objects in each group. Similar to groupBy
_.shuffle(list) Returns a shuffled copy of the list, using a version of the Fisher-Yates shuffle.
_.toArray(list) Converts the list (anything that can be iterated over), into a real Array. Useful for transmuting the arguments object.
_.size(list) Return the number of values in the list.
