javascript - 返回结果会更改 javascript JSON 字符串中的数据

Question

我有以下代码:

function bestMove() {
  var url = "http://www.api.com"; // supposed to send {"location":4} in json format.
  $.getJSON(url, function(data) {
    console.log(data);
    return data;
  });
}

$(function() {

  console.log(bestMove())
  //driver code here
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

bestMove() 中的函数 console.log(data); 记录 {location:4} (这就是我想要的)，但函数之外的记录未定义。但是，返回的是变量数据，为什么值会不同呢？

另外，当我使用 JSON.parse(data) 时，Chrome 返回此错误:

Uncaught SyntaxError: Unexpected token o in JSON at position 1
    at JSON.parse (<anonymous>)
    at Object.success (tictactoe:5)
    at u (jquery-3.3.1.min.js:2)
    at Object.fireWith [as resolveWith] (jquery-3.3.1.min.js:2)
    at k (jquery-3.3.1.min.js:2)
    at XMLHttpRequest.<anonymous> (jquery-3.3.1.min.js:2)

Answer 1

您应该能够对代码进行以下更新以实现您的目标:

function bestMove() {
  var url = "http://www.api.com"; // supposed to send {"location":4} in json format.

  // Return the result of $.getJSON 
  return $.getJSON(url, function(data) { 
    console.log(data);
    return data;
  });
}

$(function() {

  // Add a then handler after bestMove() is called. The function
  // handler will give you access to driver data returned from to
  // ajax response
  bestMove().then(function(driver) {

    //driver code here
    console.log(driver)
  })
});