Question

我试图将一个对象中的所有数组放入一个单独的二维数组中，但是函数的递归性质遇到了麻烦。我能够获得所有的数组，但是按照我编写它的方式，我得到了我不想要的多层嵌套。

下面的代码返回

[
  ["1-1","1-2","1-3"],
  [
    ["2-1","2-2","2-3"]
  ],
  [
    [
      ["3-1","3-2","3-3"]
    ]
  ],
  [
    [
      ["4-1-1","4-1-2","4-1-3"],
      [
        ["4-2-1-1","4-2-1-2","4-2-1-3"],
        ["4-2-2-1","4-2-2-2","4-2-2-3"]
      ]
    ]
  ]
]

无论对象内嵌套如何，如何修改getArrays()函数以返回二维数组？

function testGetArrays() {
  var testObject = {
    "one": ["1-1", "1-2", "1-3"],
    "two": {
      "first": ["2-1", "2-2", "2-3"]
    }, 
    "three": {
      "first": {
        "second": ["3-1", "3-2", "3-3"]
      }
    }, 
    "four": {
      "first": {
        "first": ["4-1-1", "4-1-2", "4-1-3"],
        "second": {
          "first": ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
          "second": ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
        }
      }
    }
  };
  var expectedResult = [
    ["1-1", "1-2", "1-3"],
    ["2-1", "2-2", "2-3"],
    ["3-1", "3-2", "3-3"],
    ["4-1-1", "4-1-2", "4-1-3"],
    ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
    ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
  ];
  var result = getArrays(testObject);
  console.log(JSON.stringify(expectedResult) == JSON.stringify(result));
  console.log(JSON.stringify(result));
}

function getArrays(object) {
  var result = [];
  if (Array.isArray(object)) {
    if (Array.isArray(object[0])) {
      result.push(getArrays(object[0]));
    }
    result.push(object);
  } else {
    for (var i in object) {
      current = object[i];
      if (Array.isArray(current)) {
        result.push(current);
      } else {
        var x = getArrays(current);
        result.push(x);
      }
    }
  }
  return result;
}

Answer 1

最简单的调整是为getArrays提供另一个参数result，该参数在第一次调用时被初始化为空数组，然后递归传递并进行突变：

testGetArrays();
function testGetArrays() {
  var testObject = {
    "one": ["1-1", "1-2", "1-3"],
    "two": {
      "first": ["2-1", "2-2", "2-3"]
    }, 
    "three": {
      "first": {
        "second": ["3-1", "3-2", "3-3"]
      }
    }, 
    "four": {
      "first": {
        "first": ["4-1-1", "4-1-2", "4-1-3"],
        "second": {
          "first": ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
          "second": ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
        }
      }
    }
  };
  var expectedResult = [
    ["1-1", "1-2", "1-3"],
    ["2-1", "2-2", "2-3"],
    ["3-1", "3-2", "3-3"],
    ["4-1-1", "4-1-2", "4-1-3"],
    ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
    ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
  ];
  var result = getArrays(testObject);
  console.log(JSON.stringify(expectedResult) == JSON.stringify(result));
  console.log(JSON.stringify(result));
  console.log(result);
}

function getArrays(object, result = []) {
  if (Array.isArray(object)) {
    if (Array.isArray(object[0])) {
      result.push(getArrays(object[0]));
    }
    result.push(object);
  } else {
    for (var i in object) {
      current = object[i];
      if (Array.isArray(current)) {
        result.push(current);
      } else {
        getArrays(current, result);
      }
    }
  }
  return result;
}

Answer 2

使用递归函数和ES2015：

const collectArrays = function(object){
  if (Array.isArray(object)) {
    return [object];
  }
  return Object.keys(object).reduce(function(result, key){
    result.push(...collectArrays(object[key]))
    return result;
  }, []);
}

var testObject = {
  "one": ["1-1", "1-2", "1-3"],
  "two": {
    "first": ["2-1", "2-2", "2-3"]
  },
  "three": {
    "first": {
      "second": ["3-1", "3-2", "3-3"]
    }
  },
  "four": {
    "first": {
      "first": ["4-1-1", "4-1-2", "4-1-3"],
      "second": {
        "first": ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
        "second": ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
      }
    }
  }
};

console.log(collectArrays(testObject))

Answer 3

创建一个简单的递归函数并检查键的value。如果它是一个数组，那么如果它是一个对象，则推入一个新数组，然后调用相同的递归函数

var testObject = {
  "one": ["1-1", "1-2", "1-3"],
  "two": {
    "first": ["2-1", "2-2", "2-3"]
  },
  "three": {
    "first": {
      "second": ["3-1", "3-2", "3-3"]
    }
  },
  "four": {
    "first": {
      "first": ["4-1-1", "4-1-2", "4-1-3"],
      "second": {
        "first": ["4-2-1-1", "4-2-1-2", "4-2-1-3"],
        "second": ["4-2-2-1", "4-2-2-2", "4-2-2-3"]
      }
    }
  }
};
let newArr = [];

function getKeys(obj) {
  //iterate over the object
  for (let keys in obj) {
    //check if the value is an array
    if (Array.isArray(obj[keys])) {
      // if so then push the value to another array
      newArr.push(obj[keys])
      // if not an array the recall the recursive function
    } else if (typeof obj[keys] === 'object') {
      getKeys(obj[keys])
    }
  }
}
getKeys(testObject);
console.log(newArr)

获取对象内所有数组的二维数组

3 个答案: