Question

我使用数组来存储Google地理编码API的格式化结果。在函数调用之后，我使用console.log查看数组的内容，它正常工作，但是当我尝试访问单个元素时，它返回＆＃34; undefined＆＃34;。当我检查数组长度时，我得到零。这是我的代码（addressInput是一个存储三个地址的对象）：

function startGeocode(addressInput) {
  var addressOut = [];
  var outString = "";
  var address = "";
  for(var i = 0; i < addressInput.length; i++) {
    address = addressInput[i].address + " " + addressInput[i].city + " " + addressInput[i].state + " " + addressInput[i].zip;
    geocoder.geocode({'address':address}, function(results,status) {
      if(status == 'OK') {
        outString = "" + results[0].geometry.location;
        outString = outString.replace(/\(|\)|\s/g,'');
        outString = outString.replace(/\,/g,' ');
        addressOut.push(outString);
      } else {
        outString = "Error: " + status;
        addressOut.push(outString);
      }
    });
  }
  console.log(addressOut);
  console.log(addressOut[0]);
  console.log(addressOut.length);
}

三个console.log调用返回以下内容：

/* (Using a codeblock for readability)
Array[0]
0:"(a correctly formatted latitude and longitude)"
1:"(a correctly formatted latitude and longitude)"
2:"(a correctly formatted latitude and longitude)"

addressOut[0]: undefined

addressOut.length: 0
*/

所以我的问题是，为什么我的数组长度为零，为什么我无法引用数组的元素？

Answer 1

因为您正在使用异步函数geocoder.geocode。这意味着您在此功能完成之前打印到console var。使用回调或承诺。

Javascript全局数组返回undefined

1 个答案: