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A previous function wanted to call the return value of the previous function, but its return value was always empty. Later, after looking through some information, I realized that asynchronous requests were causing trouble. I won’t go into details, but look at the example:
function get_no_order_array() { var order_info = show_order(); var order = []; $.getJSON("../JSON/customers.json", function (date) { date["man"].forEach(function (person) { if (order_info.k_obj[person] == undefined) { order.push(person); } }) }); return order; }
Later I found that the printed array order was always empty. The following is the corrected code:
function get_no_order_array() { var order_info = show_order(); var order = []; $.ajaxSettings.async = false;//在执行之前加$.ajaxSettings.async = false; (同步执行) $.getJSON("../JSON/customers.json", function (date) { //<span style="line-height: 1.5;">$.getJSON不懂的话可以看一下我之前的博客,或是专门学习一下 “JSON”</span>
date["man"].forEach(function (person) { if (order_info.k_obj[person] == undefined) { order.push(person); } }) }); $.ajaxSettings.async = true;//执行你的代码之后及时恢复为$.ajaxSettings.async = true; (异步执行) return order; }
Add $.ajaxSettings.async = false; before the loop to indicate synchronous execution, so that it will be executed in order.
Solution to the problem of data confusion caused by executing multiple $.getJSON() at the same time
Add $.ajaxSettings.async = false; before execution (synchronous execution)
Execution Your code will be restored to $.ajaxSettings.async = true in time; (asynchronous execution)
Otherwise, it will affect the code in other places that needs to be executed asynchronously.
$.ajaxSettings.async = false; $.getJSON(url, data, function(data){ }); $.getJSON(url, data, function(data){ }); $.getJSON(url, data, function(data){ }); ...... $.ajaxSettings.async = true;
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