Dart-按json值筛选数组
我有一个JSON响应:Dart-按json值筛选数组,json,flutter,dart,Json,Flutter,Dart,我有一个JSON响应: { "suggestions": [ { "label": "United States, <b>New York</b>", "language": "en", "countryCode": "USA", "locationId": "NT_rNsDLtnazM.kjVC-K6YWOA", "addres
{
"suggestions": [
{
"label": "United States, <b>New York</b>",
"language": "en",
"countryCode": "USA",
"locationId": "NT_rNsDLtnazM.kjVC-K6YWOA",
"address": {
"country": "United States",
"state": "<b>New York</b>"
},
"matchLevel": "state"
},
{
"label": "United States, <b>New York</b>, <b>New York</b>, <b>New York</b>",
"language": "en",
"countryCode": "USA",
"locationId": "NT_YpQcXqbaOb.I4m5EW8BHEC",
"address": {
"country": "United States",
"state": "<b>New York</b>",
"county": "<b>New York</b>",
"city": "<b>New York</b>",
"postalCode": "10007"
},
"matchLevel": "city"
},
{
"label": "United States, <b>New York</b>, <b>New York</b>",
"language": "en",
"countryCode": "USA",
"locationId": "NT_ABhedB4xGEL83YY5az47iD",
"address": {
"country": "United States",
"state": "<b>New York</b>",
"county": "<b>New York</b>"
},
"matchLevel": "county"
},
{
"label": "United Kingdom, NE27 0, North Shields, <b>New York</b> Way",
"language": "en",
"countryCode": "GBR",
"locationId": "NT_B24AwYSzW4TK04x9UiKMoD",
"address": {
"country": "United Kingdom",
"state": "England",
"county": "Tyne and Wear",
"city": "North Shields",
"district": "North Shields",
"street": "<b>New York</b> Way",
"postalCode": "NE27 0"
},
"matchLevel": "street"
},
{
"label": "United States, <b>New York</b>, Buffalo, <b>New York</b> State Thruway",
"language": "en",
"countryCode": "USA",
"locationId": "NT_-WyF-KGZ-pqF8zQV6NegHD",
"address": {
"country": "United States",
"state": "<b>New York</b>",
"county": "Erie",
"city": "Buffalo",
"district": "Grant Ferry",
"street": "<b>New York</b> State Thruway",
"postalCode": "14213"
},
"matchLevel": "street"
}
]
}
还尝试了以下操作:更改此操作:
var data = json.decode(res.body);
var rest = data["suggestions"] as List;
var filteredList;
rest.forEach((val) => filteredList.add(rest.where((val) => val["matchLevel"] == "city")));
print(filteredList);
为此:
var data = json.decode(res.body);
var rest = data["suggestions"] as List;
var filteredList;
filteredList = rest.where((val) => val["matchLevel"] == "city");
print(filteredList);
从:
此方法返回映射元素的视图。只要返回的Iterable
没有被迭代,就不会调用提供的函数测试。迭代不会缓存结果,因此在返回的Iterable
上多次迭代可能会在同一元素上多次调用提供的函数测试
因此,当您使用
forEach()
和where()
时,您将多次得到相同的结果。请检查以下示例:我删除了以前的注释。我的错!它起作用了。谢谢
var data = json.decode(res.body);
var rest = data["suggestions"] as List;
var filteredList;
filteredList = rest.where((val) => val["matchLevel"] == "city");
print(filteredList);