[javascript] How to make a variable accessible outside a function?

I am fetching data from a json file using $.getJSON to get an id of a character and then use $.getJSON to fetch it from another page using the id that I go previously.

However, in the console it says


It should show the id where it says unidentified - /by-summoner/undefined/summary

This is my current script:

var input = "netuetamundis";  var sID;  $(document).ready(function () {     // get json from this page to get the ID of the input     $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/" + input + "?api_key=API_KEY_HERE", function (name) {         obj = name;         sID = obj.id;         console.log(sID);     });     $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function (stats) {         console.log(stats);     }); }); 

When I googled, it said to declare the variable outside the function, which I did as you can see in the code, however it still doesn't work.

This question is related to javascript jquery

The answer is

Your variable declarations and their scope are correct. The problem you are facing is that the first AJAX request may take a little bit time to finish. Therefore, the second URL will be filled with the value of sID before the its content has been set. You have to remember that AJAX request are normally asynchronous, i.e. the code execution goes on while the data is being fetched in the background.

You have to nest the requests:

$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   obj = name;   // sID is only now available!   sID = obj.id;   console.log(sID); }); 

Clean up your code!

  • Put the second request into a function
  • and let it accept sID as a parameter, so you don't have to declare it globally anymore! (Global variables are almost always evil!)
  • Remove sID and obj variables - name.id is sufficient unless you really need the other variables outside the function.

$.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/"+input+"?api_key=API_KEY_HERE"  , function(name){   // We don't need sID or obj here - name.id is sufficient   console.log(name.id);    doSecondRequest(name.id); });  /// TODO Choose a better name function doSecondRequest(sID) {   $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function(stats){         console.log(stats);   }); } 

Hapy New Year :)

$.getJSON is an asynchronous request, meaning the code will continue to run even though the request is not yet done. You should trigger the second request when the first one is done, one of the choices you seen already in ComFreek's answer.

Alternatively you could use jQuery's $.when/.then(), similar to this:

var input = "netuetamundis";  var sID;  $(document).ready(function () {     $.when($.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.1/summoner/by-name/" + input + "?api_key=API_KEY_HERE", function () {         obj = name;         sID = obj.id;         console.log(sID);     })).then(function () {         $.getJSON("https://prod.api.pvp.net/api/lol/eune/v1.2/stats/by-summoner/" + sID + "/summary?api_key=API_KEY_HERE", function (stats) {             console.log(stats);         });     }); }); 

This would be more open for future modification and separates out the responsibility for the first call to know about the second call.

The first call can simply complete and do it's own thing not having to be aware of any other logic you may want to add, leaving the coupling of the logic separated.