javascript - 如何在 UnderScore.js 中创建嵌套分组依据

Question

我有一个数组，我需要根据 size_y 对它们进行分组；

[
    {"col":4,"row":1,"size_x":1,"size_y":4}, 
    {"col":2,"row":2,"size_x":1,"size_y":2}, 
    {"col":1,"row":1,"size_x":3,"size_y":1},
    {"col":1,"row":4,"size_x":3,"size_y":1}, 
    {"col":1,"row":5,"size_x":4,"size_y":1}
]

现在，如果 size_y 为 4，我想对所有小于或等于 4 的行进行分组。

[
    {"col":4,"row":1,"size_x":1,"size_y":4}, 
    {"col":2,"row":2,"size_x":1,"size_y":2}, 
    {"col":1,"row":1,"size_x":3,"size_y":1},
    {"col":1,"row":4,"size_x":3,"size_y":1},
],
[
    {"col":1,"row":5,"size_x":4,"size_y":1}
]

提前致谢。

Answer 1

您可以使用生成器函数和.splice()

let arr = [
    {"col":4,"row":1,"size_x":1,"size_y":4}, 
    {"col":2,"row":2,"size_x":1,"size_y":2}, 
    {"col":1,"row":1,"size_x":3,"size_y":1},
    {"col":1,"row":4,"size_x":3,"size_y":1}, 
    {"col":1,"row":5,"size_x":4,"size_y":1}
];

function* divideBy(a) {
  const [copy, [{size_y}] = copy] = [[...a]];
  while (copy.length) yield copy.splice(0, size_y);
}

let res = [...divideBy(arr)];

console.log(res)