jQuery用函数返回值更改文本[重复]

I would like to change the text of each div with the class "container". I have a function test1, which will call after a click on a button. This function should change the text with return values of function test2. but the text will not be changed. alert(result) shows the correct text which I expect. How can I solve this issue?

<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>


function test1() {
   $( ".container" ).each(function() { 
      $( ".container" ).text(test2('MyValue'));
   })
}

function test2(value) {  
   $.getJSON("ajax.php", {
      value: value
   }, function(result) {
        alert(result);
        return result;  
   })
}

</div>

You can't change the text until the AJAX is done.. Promises are a good solution..

<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>
<div class="container">Some text</div>


function test1() {
   test2('myValue').then(res=>$( ".container" ).text(res))
}

function test2(value) { 
   return new Promise(done=>
   $.getJSON("ajax.php", {
      value: value
   }, function(result) {
        done(result); 
   }));
}