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Diffstat (limited to 'general-util.js')
-rw-r--r-- | general-util.js | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/general-util.js b/general-util.js index 879219d..2ce7ed4 100644 --- a/general-util.js +++ b/general-util.js @@ -63,3 +63,27 @@ module.exports.downloadPlaylistFromOptionValue = function(arg) { return downloadPlaylistFromLocalPath(arg) } } + +module.exports.shuffleArray = function(array) { + // Shuffles the items in an array. Returns a new array (does not modify the + // passed array). Super-interesting post on how this algorithm works: + // https://bost.ocks.org/mike/shuffle/ + + const workingArray = array.slice(0) + + let m = array.length + + while (m) { + let i = Math.floor(Math.random() * m) + m-- + + // Stupid lol; avoids the need of a temporary variable! + Object.assign(workingArray, { + [m]: workingArray[i], + [i]: workingArray[m] + }) + } + + return workingArray +} + |