functionconcat$(x, ...ys)// x:  an array (updated!)// ys: arrays to append

constxarray=require('extra-array');varx=[1,2];vary=[3,4];xarray.concat$(x,y);// → [ 1, 2, 3, 4 ]x;// → [ 1, 2, 3, 4 ]varx=[1,2];xarray.concat$(x,y,y);// → [ 1, 2, 3, 4, 3, 4 ]

References