在JavaScript中获得两个数组的并集

如果您不需要保留订单，并考虑

45

"45"

function union_arrays (x, y) {  var obj = {};  for (var i = x.length-1; i >= 0; -- i)     obj[x[i]] = x[i];  for (var i = y.length-1; i >= 0; -- i)     obj[y[i]] = y[i];  var res = []  for (var k in obj) {    if (obj.hasOwnProperty(k))  // <-- optional      res.push(obj[k]);  }  return res;}console.log(union_arrays([34,35,45,48,49], [44,55]));