在 navigator.geolocation.getCurrentPosition 之外保存变量?(javascript)
我正在尝试使用 js 的范围从 navigator.geolocation.getCurrentPosition 中拉出一个变量
I'm trying to play with the scope of js to pull a variable out of navigator.geolocation.getCurrentPosition
var lat;
function callback (position) {
lat = position.coords.latitude;
}
navigator.geolocation.getCurrentPosition(callback,fail,{timeout:10000});
// after getCurrentPosition succeeds
alert(lat); // this alerts null
上面的代码因为作用域的原因,不能将 position.coords.latitude 存储在 lat 变量中.有没有办法做到这一点?
The above code cannot store position.coords.latitude in the lat variable because of the scope. Is there a way to do this?
推荐答案
你必须记住 asyncajax 的本质.
You have to remember the asyncajax nature.
这是你的代码的执行顺序:
this is the execution order of your code:
var lat;
alert(lat); // this alerts null
navigator.geolocation.getCurrentPosition(callback,fail,{timeout:10000});
function callback (position) {
lat = position.coords.latitude;
}
这就是你得到 null 的原因.异步!,异步! :)
This why you get null. async!, async! :)
相关文章