Question

我使用map从多维数组中获取点，但是我得到了数组值数组。

我需要以下格式：

[36, 122, 25]

但是我得到了多点积分。

以下是我的代码和输出

＆＃13;

var data = [{
    "name": "ramu",
    "id": "719",
    "gmail": "ramu@gmail.com",
    "ph": 988989898,
    "points": 36
  },
  {
    "name": "ravi",
    "id": "445",
    "gmail": "ravi@gmail.com",
    "ph": 4554545454,
    "points": 122
  },
  {
    "name": "karthik",
    "id": "866",
    "gmail": "karthik@gmail.com",
    "ph": 2332233232,
    "points": 25
  }
]

var result = data.map(function(arr, count) {
  return [arr.points];
});

console.log(result);

＆＃13;

输出是：

[[36], [122], [25]]

Answer 1

尝试以下代码：

var data = [{"name":"ramu","id":"719","gmail":"ramu@gmail.com","ph":988989898,"points":36},
        {"name":"ravi","id":"445","gmail":"ravi@gmail.com","ph":4554545454,"points":122},
        {"name":"karthik","id":"866","gmail":"karthik@gmail.com","ph":2332233232,"points":25}]          
var result = data.map(function(arr, count) {  return arr.points;});
console.log(result);

Answer 2

＆＃13;

var data = [{"name":"ramu","id":"719","gmail":"ramu@gmail.com","ph":988989898,"points":36},
            {"name":"ravi","id":"445","gmail":"ravi@gmail.com","ph":4554545454,"points":122},
            {"name":"karthik","id":"866","gmail":"karthik@gmail.com","ph":2332233232,"points":25}]          
var result = data.map(function(arr, count) {  return arr.points;});
console.log(result);

＆＃13;

从return语句中删除[]。它创建新阵列并将其推送到原始阵列。

Answer 3

该函数返回单元素数组的数组，因为.map()返回一个数组，并且在.map()的每次迭代中，您的函数返回[arr.points]（数组中的元素）。将此更改为返回arr.points并重新设置。

此外，由于您只是在.map()中返回一个值，我们可以将回调函数简化为：

var result = data.map(arr => arr.points);

＆＃13;

var data = [{
    "name": "ramu",
    "id": "719",
    "gmail": "ramu@gmail.com",
    "ph": 988989898,
    "points": 36
  },
  {
    "name": "ravi",
    "id": "445",
    "gmail": "ravi@gmail.com",
    "ph": 4554545454,
    "points": 122
  },
  {
    "name": "karthik",
    "id": "866",
    "gmail": "karthik@gmail.com",
    "ph": 2332233232,
    "points": 25
  }
]
var result = data.map(arr => arr.points);
console.log(result);

＆＃13;

Answer 4

在您的代码中，您使用[]使用arr.points值创建新数组。从return语句中删除[]。

＆＃13;

var data = [{
    "name": "ramu",
    "id": "719",
    "gmail": "ramu@gmail.com",
    "ph": 988989898,
    "points": 36
  },
  {
    "name": "ravi",
    "id": "445",
    "gmail": "ravi@gmail.com",
    "ph": 4554545454,
    "points": 122
  },
  {
    "name": "karthik",
    "id": "866",
    "gmail": "karthik@gmail.com",
    "ph": 2332233232,
    "points": 25
  }
]
var result = data.map(function(arr, count) {
  return arr.points;
});
console.log(result);

＆＃13;

使用javascript动态推送元素

4 个答案: