我正在获取此 JSON 文件。路径数组可以是从 1 到 100,
{
"waypoints": [
{
"path0": [
{
"color": "#0000FF"
},
{
"lat": "37.9875000",
"lon": "23.7609260"
},
{
"lat": "37.9873130",
"lon": "23.7607460"
},
{
"lat": "37.9873840",
"lon": "23.7604100"
}
],
"path1": [
{
"color": "#00FF00"
},
{
"lat": "37.9873840",
"lon": "23.7604100"
},
{
"lat": "37.9878040",
"lon": "23.7605670"
},
{
"lat": "37.9882590",
"lon": "23.7607340"
}
],
"path2": [
{
"color": "#FF0000"
},
{
"lat": "37.9882590",
"lon": "23.7607340"
},
{
"lat": "37.9884690",
"lon": "23.7598760"
}
]
}
]
}
如何查看 Javascript 中的 waypoints
中有多少个路径(path0、path1、..)数组?
使用 obj.waypoints.length 返回 0。
谢谢。
最佳答案
在现代浏览器上,您可以使用 Object.keys :
var nbpaths = Object.keys(obj.waypoints[0]).length;
为了兼容ie8,你可以这样算:
var nbpaths = 0;
for (var key in obj.waypoints[0]) nbpaths++;
关于javascript - 计算Json数组中的数组数量,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16786356/