1. by slice
var arr = [1, 2, 3] ;
copyArr = arr.slice(0);
2. by concat
var arr = [1, 2, 3] ;
copyArr = arr.concat();
var arr = [1, 2, 3] ;
copyArr = arr.slice(0);
2. by concat
var arr = [1, 2, 3] ;
copyArr = arr.concat();