$.json call jQuery doesn't return a value into a variable

Question

i've got a problem with a $.json jQuery call function, this is my code :

// function to get currency live rates from yahoo api keys

function getRate(from, to) {        
  $.getJSON('http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22'+from+to+'%22)&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=', function(data) {

    var rate  = data.query.results.rate.Rate; 

    return rate; 

  });

}// end of function

var receive = getRate('USD','EUR');

Answer 1

Finally i found the solution of return a value into a variable with $.ajax call function, check the code above, works perfect for me, btw thank you all guys :)

var rate = [ ]; // Step 1 , we create a new array, usefull because we will store here the return value

// Step 2 , we create our function below

function getRate(from,to) {

//Step 3, the ajax call inside a variable

var ajaxCall = $.ajax({

async:false,
dataType:"json",
type:'GET',
url:'http://query.yahooapis.com/v1/public/yql?q=select%20*%20from%20yahoo.finance.xchange%20where%20pair%20in%20(%22'+from+to+'%22)&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys&callback=',
success: function(data) {
result = data.query.results.rate.Rate;
rate.push(result); //we push the result into the array

} });// ajax call end

if(rate.indexOf()<=0) {

ajaxCall.abort();
return calc;

}

}//function finish here

// and then voilà :)

var returnValue = getRate('USD','EUR');

// now do whatever you want

// for example :

alert(returnValue);