如何用javascript将父子数组转换为json树结构

function arrayToTree(arr, parentId) {
  var tree = [];
  for (var i = 0; i < arr.length; i++) {
    if (arr[i].parent_id === parentId) {
      var children = arrayToTree(arr, arr[i].id);
      if (children.length > 0) {
        arr[i].children = children;
      }
      tree.push(arr[i]);
    }
  }
  return tree;
}

var arr = [
  { id: 1, name: "Parent 1", parent_id: 0 },
  { id: 2, name: "Child 1-1", parent_id: 1 },
  { id: 3, name: "Child 1-2", parent_id: 1 },
  { id: 4, name: "Parent 2", parent_id: 0 },
  { id: 5, name: "Child 2-1", parent_id: 4 },
];

var jsonTree = arrayToTree(arr, 0);
console.log(JSON.stringify(jsonTree));