set

2024年04月08日

柏拉文

越努力，越幸运

一、认识

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二、实现

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2.1 Bolawen reduce

实现

function set(obj, path, value) {
  const pathRegExp = /[,\[\].]+?/;
  const keys = Array.isArray(path)
    ? path
    : path.split(pathRegExp).filter(Boolean);

  keys.reduce((acc, key, index) => {
    if (index === keys.length - 1) {
      acc[key] = value;
    } else {
      if (!acc[key]) {
        acc[key] = {};
      }
      return acc[key];
    }
  }, obj);
}

测试

const object = { a: [{ b: { c: 3 } }] };

set(object, "a[0].b.c", 4);
console.log(object.a[0].b.c);
// => 4

set(object, ["x", "0", "y", "z"], 5);
console.log(object.x[0].y.z);
// => 5

2.2 Bolawen for…of

实现

function set(obj, path, value) {
  const pathRegExp = /[,\[\].]+?/;
  const keys = Array.isArray(path)
    ? path
    : path.split(pathRegExp).filter(Boolean);

  for (const key of keys.slice(0, -1)) {
    if (!obj[key]) {
      obj[key] = {};
    }
    obj = obj[key];
  }

  obj[keys[keys.length - 1]] = value;
}

测试

const object = { a: [{ b: { c: 3 } }] };

set(object, "a[0].b.c", 4);
console.log(object.a[0].b.c);
// => 4

set(object, ["x", "0", "y", "z"], 5);
console.log(object.x[0].y.z);
// => 5