匿名函數內循環內變量作用域

Question

我試圖在Google地圖中創建交互式標記。這裏是陣列來創建標記：

var markers = [ 
    {"id":17,"ti":"33 Star Hotel","lat":3.14648,"lng":101.711,"ty":5,"lid":"3","desc":""}, 
    {"id":9,"ti":"Aquaria KLCC","lat":3.15392,"lng":101.713,"ty":10,"lid":"3","desc":""}, 
    {"id":28,"ti":"Batu Ferringhi","lat":5.47436,"lng":100.247,"ty":15,"lid":"4","desc":""}, 
]; 

的標記被添加到地圖Ñ如果所述標記的位置ID 蓋是等於n。

當點擊一個標記，我希望被顯示的標記數組索引，但它們都顯示出我（markers.length）的最終值。

function map_center(n) { 
    for (var i = 0; i < markers.length; i++) { 
     if (markers[i].lid == n) { 
      var m = new google.maps.Marker({ 
       position: { lat: markers[i].lat, lng: markers[i].lng }, 
       map: map, 
       title: markers[i].ti, 
       icon: icons[markers[i].ty], 
      }); 
      m.addListener("click", function(){ 
       alert("click:" + i); 
      }); 
      markers[i].dom = m; 
     } 
    } 
} 

不知何故，匿名函數需要一個參數來獲得我當前值的副本。我在這裏發現了這個解決方案對SO和它的作品，但我不喜歡傳遞參數是這樣的：

var m = new google.maps.Marker({ 
    position: { lat: markers[i].lat, lng: markers[i].lng }, 
    map: map, 
    title: markers[i].ti, 
    icon: icons[markers[i].ty], 
    i: i 
}); 
m.addListener("click", function(){ 
    alert("click:" + this.i); 
}); 

如何來正確地完成？

Answer 1

裹一切都在一個iife

function map_center(n) { 
for (var i = 0; i < markers.length; i++) { 
    (function(i) { 
     if (markers[i].lid == n) { 
      var m = new google.maps.Marker({ 
       position: { lat: markers[i].lat, lng: markers[i].lng }, 
       map: map, 
       title: markers[i].ti, 
       icon: icons[markers[i].ty], 
      }); 
      m.addListener("click", function(){ 
       alert("click:" + i); 
      }); 
      markers[i].dom = m; 
     } 
    })(i) 
}