“Zeroes out” an array with any replacement value. Given an array of
var scores = [15, 22, 3, 7, 11];
“Wiping out” every record in the array and viewing the result in the console:
scores.fill(0); > [0, 0, 0, 0, 0]
fill can take two other arguments: the first,
start is the point from which the fill will take place. Taking the current state of
scores, we can fill from the third value with:
> [0, 0, 4, 4, 4]
fill can also take an
end value, where the fill stops. Of course, the fill “insert” value can be anything you wish: a number, string, or
null, for example.
fill is part of ES6 / JS 2015, and is therefore supported in all recent browser versions except for IE and Opera; Mozilla Developer Network suggests a polyfill for those and older browser versions.
reverse reverses the order of elements. Given an array
var molluscs = ["oysters", "mussels", "limpets"];
Reversing the array and showing the results in the console:
molluscs.reverse() > ["limpets", "mussels", "oysters"]
Photograph by Risto Kuulasmaa, used under a Creative Commons Attribution-NonCommercial 2.0 Generic license.
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