Question

我有一个包含词典的数组。像这样：

[{date:1991, value: 78}, {date:1992, value: 102}, {date:1993, value: 277}]

使用日期搜索对象的好方法是：1991并返回值？

Answer 1

您可以使用Array#find方法。

var data = [{
    date: 1991,
    value: 78
  }, {
    date: 1992,
    value: 102
  }, {
    date: 1993,
    value: 277
  }],
  date = 1991;

console.log(
  (data.find(function(v) {
    return v.date == date;
  }) || {}).value
)

对于较旧的浏览器，请检查polyfill option of find method。

Answer 2

使用filter()方法，您可以将其作为

const dict = [ {date:1991, value: 78}, 
              {date:1992, value: 102}, 
              {date:1993, value: 277} ]

console.log(dict.filter(obj => obj.date === 1991))

如果您想在简单的for和if循环中回答，您也可以使用用户定义的函数执行相同的操作。

var dict = [{date:1991, value: 78}, {date:1992, value: 102}, {date:1993, value: 277}]

function search_obj(dict, year) {
  for (obj of dict) {
    if (obj.date === year) {
      return obj
    }
  }
}

console.log(search_obj(dict, 1991))

Answer 3

创建自己的搜索功能。

var arr = [{date:1991, value: 78}, {date:1992, value: 102}, {date:1993, value: 277}];

function searchFn(searchDate){

    for(var i = 0; i < arr.length; i++)
        if(arr[i] == searchDate)
            return arr[i];
}

//search
searchFn(1991);//{date:1991, value: 78}
searchFn(1992);//{date:1992, value: 102}

Answer 4

只需使用forEach方法。

＆＃13;

var arr=[{date:1991, value: 78}, {date:1992, value: 102}, {date:1993, value: 277},{date:1991, value: 79}];
var v=1991,ans=[];

arr.forEach(function(a){
if(a.date==v)
   ans.push(a.value);
});
console.log(ans);

＆＃13;

Answer 5

使用简单的过滤语句：

var data = [{date:1991, value: 78}, {date:1992, value: 102}, {date:1993, value: 277}]
var result = data.filter(x => x.date == 1991)
console.log(result)

通过搜索特定值返回Array中的Dictionary对象

5 个答案: