access javascript variable outside scope

I have

jQuery(document).ready(function() 
{

    jQuery.get('data/php/traces_pos.csv', function(data) { var routes = jQuery.csv()(data); });

//if I use here 

for (i=0;i<=routes.length;i++){}

// javascript says route undefined

}

How do I access the routes which is a array 开发者_开发问答of arrays

Define routes outside the callback:

var routes;
jQuery.get('data/php/traces_pos.csv', function(data) { routes = jQuery.csv()(data); });

You need to wait until routes has been set. I'm using a function and passing in routes as a parameter:

jQuery(document).ready(function() 
{

    jQuery.get('data/php/traces_pos.csv', function(data) {  
        var routes = jQuery.csv()(data); 
        performRoutes(routes);
    });
});

//if I use here 
function performRoutes(routes) {
    for (i=0;i<=routes.length;i++){
        // routes
    }
}

You have to define routes outside of either function, as such:

var routes;

jQuery(document).ready(function() 
{

    jQuery.get('data/php/traces_pos.csv', function(data) {  routes = jQuery.csv()(data); });

//if I use here 

for (i=0;i<=routes.length;i++){}

//  routes is no longer undefined

}

Moving the declaration of routes outside the jQuery.get call will make it visible to your for loop -- but beware that your for loop runs before the callback is called, so routes will not have been set yet.

Anything you do that depends on the result of an asynchronous get must be either inside the callback function or in code that is called from within the callback function. In the latter case, you can pass your routes as a parameter at the function call -- there is no need to widen the variable's scope.