Question

下面是我的数组：

var myArray = [
    {field: 'region1.mp3.california', flag: false}, 
    {field: 'region1.mp3.marines,region1.mp3.region2.mp3.california', flag: false},
    {field: 'region2.mp3.california', flag: false}, 
    {field: 'region2.mp3.abc', flag: false}, 
    {field: 'region3.mp3.abc', flag: false}, 
];

var regions = ["region1.mp3", "region2.mp3","region3.mp3"];

现在这里的数据在第二个点之后属于特定区域。

例如： region1.mp3.california，region1.mp3.marines

california and marines belongs to region1.

所以这里我试图比较区域数组和myArray的长度，并根据myarray数据和区域数组数据长度应该相等，因为myarray包含来自区域数组的所有区域数据，因此它们的长度应相等。

预期输出：true

我没有到达如何使用reduce函数进行比较。

＆＃13;

var myArray = [
    {field: 'region1.mp3.california', flag: false}, 
    {field: 'region1.mp3.marines,region1.mp3.region2.mp3.california', flag: false},
    {field: 'region2.mp3.california', flag: false}, 
    {field: 'region2.mp3.abc', flag: false}, 
    {field: 'region3.mp3.abc', flag: false}, 
];

var regions = ["region1.mp3", "region2.mp3","region3.mp3"];

var len1 = regions.length;
var len2 = myArray.reduce(function (p, c) {
                return p.concat(c.field.split(','));
            }, []).length;
            
            if(len1 == len2)
               console.log(true)
               else
               console.log(false)

＆＃13;

Answer 1

尝试此reduce函数调用：

const MyDatePicker = ({ input, meta: { touched, error } }) => (
  <div>
    <DatePicker
      {...input} dateFormat="DD-MM-YYYY"
      selected={input.value ? moment(input.value, 'DD-MM-YYYY') : null}
    />
    {touched && error && <span>{error}</span>}
  </div>
);

Answer 2

我首先使用Array.prototype.map()创建一个仅包含.field.split('.')\[0\]的新数组，其中包含region1或'region2'或'region3'。此数组的大小与myArray

相同

然后我使用Array.prototype.filter()删除重复区域。此数组仅包含region1，region2和region3

var myArray = [
    {field: 'region1.mp3.california', flag: false}, 
    {field: 'region1.mp3.marines,region1.mp3.region2.mp3.california', flag: false},
    {field: 'region2.mp3.california', flag: false}, 
    {field: 'region2.mp3.abc', flag: false}, 
    {field: 'region3.mp3.abc', flag: false}, 
];

var regions = ["region1.mp3", "region2.mp3","region3.mp3"];
var myArrayRegions = [];

myArrayRegions = myArray.map(function(o){
  return o.field.split('.')[0];
}).filter(function(item, pos, self) {
    return self.indexOf(item) == pos;
});

console.log(JSON.stringify(myArrayRegions));
console.log(JSON.stringify(regions));

详细代码

var myArray = [
    {field: 'region1.mp3.california', flag: false}, 
    {field: 'region1.mp3.marines,region1.mp3.region2.mp3.california', flag: false},
    {field: 'region2.mp3.california', flag: false}, 
    {field: 'region2.mp3.abc', flag: false}, 
    {field: 'region3.mp3.abc', flag: false}, 
];

var regions = ["region1.mp3", "region2.mp3","region3.mp3"];
var myArrayRegions = [];

//Create a new array with each element being the result of the callback function.
myArrayRegions = myArray.map(function(o){
  //o ==> {field: 'region1.mp3.california', flag: false}
  //o.field ==> region1.mp3.california
  //o.field.split('.') ==> ['region1','mp3','california']
  //o.field.split('.')[0] ==> 'region1'
  return o.field.split('.')[0];
});
console.log(JSON.stringify(myArrayRegions));

//Filter the array to remove duplicates
myArrayRegions = myArrayRegions.filter(function(item, pos, self){
  return self.indexOf(item) == pos;
});
console.log(JSON.stringify(myArrayRegions));

注意

您只是比较两个数组的长度。 myArray可能包含region4，region5和region6，它仍会返回true，因为这两个数组的长度均为3

在第一个点之后拆分字符串并比较2个数组

2 个答案: