Question

给出一个数组：

var nationList = ["Austria", "France", "Austria", "Spain", "Austria"]

鉴于以下内容获得了当前的svg path属性（我正在使用http://jsfiddle.net/0jh3fud9/2/，因此该值位于json中）。

var countryName = e.target.feature.properties.name;

我运行以下命令，发现leaflet map，基本上是当我将鼠标悬停在一个多边形上时，得到countryName并检查该数组中有多少次：

var fours = nationList.filter(function(it) {return it === countryName;});
var result = fours.length;

但是，如果我这样做：console.log(result);总是给我1或0，如果没有匹配项。

在实际情况下，console.log(nationList);的示例给出：

["Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan", "Afghanistan",

UDPATE

我之前所做的是尝试计算每个值：

  var count = [];
  nationList.sort();
  nationList.forEach(function(i) { 
    var i = i.replace(/^\s+/g, "");
    count[i] = (count[i]||0) + 1;
  });
  console.log(count);

这很好，例如：Austria: 22

但是当我这样做时：

function onEachFeature(feature, layer) {
  layer.on({
    click: selectNation,
    mouseover: printCount
  });
}

function printCount(e) {
  var countryName = e.target.feature.properties.name;
  var filteredNations = nationList.filter( nation => nation ===countryName);
  var result = filteredNations.length;
  console.log(result);
}

每次我用mouse hover path和property name时，都说奥地利，甚至在array中，我们也有很多重复出现，如果有匹配项，则console给我1或0

Answer 1

您发布的代码似乎可以正常工作，但是正如GetOffMyLawn所述，您应该将两者以相同的情况进行比较，以确保确定。

var nationList = ["Austria", "France", "Austria", "Spain", "Austria"];
var countryName = e.target.feature.properties.name;
var fours = nationList.filter(
  function(it) {
    return it.toLowerCase() === countryName.toLowerCase();
  });
var result = fours.length;

console.log(result);

很抱歉，答案很短，但目前声誉不足，只能发表评论。

如何获得一个匹配值多少次？

1 个答案: