filter

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2023-12-01

Creates a new sequence whose values are the elements of this sequence which satisfy the specified predicate.

Signature

Sequence.filter = function(filterFn) { /*...*/ }

Sequence.filter = function filter(filterFn) {
  return new FilteredSequence(this, createCallback(filterFn));
}

Name	Type(s)	Description
filterFn	Function	The predicate to call on each element in this sequence, which returns true if the element should be included.
returns	Sequence	The new sequence.

Examples

var numbers = [1, 2, 3, 4, 5, 6];

Lazy(numbers).filter(isEven) // sequence: [2, 4, 6]

Benchmarks

function isEven(x) { return x % 2 === 0; }

var smArr = Lazy.range(10).toArray(),
lgArr = Lazy.range(100).toArray();

Lazy(smArr).filter(isEven).each(Lazy.noop) // lazy - 10 elements
Lazy(lgArr).filter(isEven).each(Lazy.noop) // lazy - 100 elements
_.each(_.filter(smArr, isEven), _.noop)    // lodash - 10 elements
_.each(_.filter(lgArr, isEven), _.noop)    // lodash - 100 elements

Implementation	10 elements	100 elements
lazy
lodash