Question

我正在尝试通过键lat访问JSON文件中的特定值，因为我循环遍历每条记录。但是，当我打印它时，我得到undefined结果。

JSON

[{"pid":4317129482,"lat":"51.5078","lon":"-0.10467","coords":{"x":-0.10467,"y":51.5078},"points":{"x":-0.10467,"y":51.5078}},
{"pid":4356791546,"lat":"51.522","lon":"-0.101773","coords":{"x":-0.101773,"y":51.522},"points":{"x":-0.101773,"y":51.522}},

JSON存储在data

中

代码尝试

$.each(data, function(key, value){  
                            if (key == "lat") {
                                console.log(value)
                            }

OR

$.each(data, function(item){    
                            console.log(item.lat)
}

Answer 1

如果你发布的JSON是正确的，那么它就是一个对象数组。所以$.each(data,function(key,val){})将返回索引，对象即key为0,1,2并对该对象赋值。

访问

＆＃34; LAT＆＃34;：＆＃34; 51.522＆＃34;

你必须这样做

$.each(data,function(key,val){
    //val here is your object. For each object in the array you have to loop again 
    $.each(val,function(k,v){
        //now since val is an object looping through it will return your key-value pairs
        if(k == 'lat'){
        //Do something
        }
    })
})

Answer 2

试试这个

$.each(data, function(key, value){
   console.log(value.lat); 
});

Answer 3

如果它有助于更改参数名称更多地表明您使用$.each

进行循环

对于像：

这样的数组

$.each(arr, function(index, arrayElement){

})

对象

$.each(obj, function(objKey, propertyValue){

});

当不确定循环中的内容使用console.log([index, arrayElement])时，您可以在浏览器开发工具控制台中检查它

如何使用$ .each（）通过键访问JSON中的特定值

3 个答案: