Reverse an array.
$ npm install compute-reverse
For use in the browser, use browserify.
var reverse = ;
reverse( arr[, options] )
var arr = 1 2 3 4 ;var out = ;// returns [ 4, 3, 2, 1 ]
By default, the input
array is mutated. To return a new
array, set the
copy option to
var arr = 1 2 3 4 ;var out =;// returns [ 4, 3, 2, 1 ];console;// returns false
var reverse = ;var arr = 100 ;for var i = 0; i < arrlength; i++arr i = i;;console;
To run the example code from the top-level application directory,
$ node ./examples/index.js
According to ECMA specification 262, when implementing the native
array.reverse() method, one must check whether
array elements are defined before determining how to swap elements. If one element is a
hole, only the non-hole value is assigned to a temporary value before being assigned to a new position in the
array. The element's original position is then deleted. See the V8 (Node.js) implementation for an example.
If we eliminate the
hole checks and additional temporary variables, we can streamline the algorithm for performance gains. See jsPerf for benchmarks.
$ make test
All new feature development should have corresponding unit tests to validate correct functionality.
This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:
$ make test-cov
Istanbul creates a
./reports/coverage directory. To access an HTML version of the report,
$ make view-cov
Copyright © 2014-2015. Athan Reines.