javascript - 比较数组并相加？

Question

我有两个数组

Data = [
"year": 2001, "count": 35,
"year": 2002, "count": 15,
"year": 2005, "count": 2
]

Years = [2000, 2001, 2002, 2003, 2004, 2005, 2006]

我想要做的是:检查Data中是否存在Years，如果不存在，则将“year”添加到Data中，“计数”为 0。

到目前为止我所能做的就是检查它们是否在那里。

Data = [
  "year": 2001, "count": 35,
  "year": 2002, "count": 15,
  "year": 2005, "count": 2
]

Years = [2000, 2001, 2002, 2003, 2004, 2005, 2006]

for (var i = 0; i < Data.length; i++) {
  $(Years).each(function(value) {
    if (Data.indexOf(Years[value]) != -1) {
      console.log("missing one");
    };
  })
}

Answer 1

如果我假设您的Data是一个对象数组，那么您可以像这样继续:

const Data = [
  {"year": 2001, "count": 35},
  {"year": 2002, "count": 15},
  {"year": 2005, "count": 2}
];

const Years = [2000, 2001, 2002, 2003, 2004, 2005, 2006];

Years.forEach(x =>
{
    if (!Data.some(({year}) => year === x))
        Data.push({year: x, count: 0});
})

console.log(Data);

// If you need to sort by year, then you could do this:

Data.sort((a,b) => a.year - b.year);
console.log(Data);

如果你追求性能，那么你可以先创建一个Set()已经存在的年份，以便以后改进推送算法。

const Data = [
  {"year": 2001, "count": 35},
  {"year": 2002, "count": 15},
  {"year": 2005, "count": 2}
];

const Years = [2000, 2001, 2002, 2003, 2004, 2005, 2006];
const dataYears = new Set(Data.map(({year}) => year));

Years.forEach(x =>
{
    if (!dataYears.has(x))
        Data.push({year: x, count: 0});
})

console.log(Data);