javascript - The loading order of Js code and ajax request of Jquery in the Dom -

function f(){ $.post('1.php',{},function(){window.location.href="../../2.php";}); } 

when click button,excute function f.the code above can run correctly , achieve wanted function.but when code changes follow format:

function f(){ $.post('1.php',{},function(){}); window.location.href="../../2.php"; } 

the ajax request not work.i know has javascript load order,but want make clear in deep level.it nice of me , explain in detail.thank you!

when have

$.post('1.php',{},function(){}); window.location.href="../../2.php"; 

the second line executed first 1 has been executed. first statement launches ajax request, doesn't block until browser has sent whole request server.

as second line replaces page, stops script , tells browser can stop being doing page, querying server.

the solution have in first code :

$.post('1.php',{},function(){window.location.href="../../2.php";}); 

the window.location change done when browser has received answer.