使用php mysql和js操纵动态输入

I have a table named description:

CREATE TABLE description(
  word_id int(11),
  word varchar (50),
  PRIMARY KEY (word_id)
);

and I try to get all word in this table and for every word I create a checkbox with value and id equal at a value of the word that I get from table description, if the checkbox is checked, I save his value in var abcd.

<?php
///connection
$get_word = $bdd->query("SELECT * FROM description");
while ($donnees = $get_word->fetch()) {
?>
    <input type="checkbox" id="<?php $donnees["word"] ?>" value="<?php $donnees["word"] ?>">
    <br>

    <script>
    $('#<?php $donnees["word"] ?>').on('change', function() {
        var abcd= this.checked ? this.value : '';
    });
    </script> 
<?php
}
?>

Now, I want to create a button out of boocle while , if this button is clicked,it must give me the value of checkbox checked.

Here's how you could do it using jQuery. As you already have the PHP logic, my example demonstrates the jQuery code only:

$(document).ready(function() {
    'use strict';
    $("#getCheckedBoxes").on('click', () => {
      $('input[type="checkbox"]').each(function(i, el){
        if($(el).is(':checked'))
          console.log($(el).val())
      })
    })
})

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input type="checkbox" value="Item 1">Item 1
<input type="checkbox" value="Item 2">Item 2
<input type="checkbox" value="Item 3">Item 3
<button id="getCheckedBoxes">Get checked boxes</button>

</div>

hope this will solve your problem

PHP code

<?php
///connection
  $get_word=$bdd->query("SELECT * FROM description");
 while ($donnees = $get_word->fetch()) {
 ?>
<input type="checkbox" id="myid_<?php $donnees["word"] ?>" onclick="myfunc(<?php $donnees["word"] ?>)" value="<?php $donnees["word"] ?>"><br> 
 <?php
 }
?>

JS CODE

<script>
function myfunc(word){
  if(document.getElementById('myid_'+word).checked == true){
   var check_val = document.getElementById('myid_'+word).value;
   alert(check_val);
  }
}
</script>

or you can do this

<script>
function myfunc(word){
  if(document.getElementById('myid_'+word).checked == true){
   alert(word);
  }
}
</script>

add class name such as clickable to your input tag. after all rendering in php add script that runs when any input with clickable class changed and you can get that tag!

<?php
$get_word=$bdd->query("SELECT * FROM description");
while ($donnees = $get_word->fetch()) { ?>
<input class="clickable" type="checkbox" id="<?php $donnees["word"] ?>" value="<?php $donnees["word"] ?>">
<?php } ?>

<script>
$('.clickable').on('change', function(item) {
    console.log(item)
});
</script> 

I try this

///connection
    $get_word=$bdd->query("SELECT * FROM description");
     while ($donnees = $get_word->fetch()) {
     ?>
     <label><?php echo $donnees["word"] ?></label>
    <input type="checkbox" id="myid_<?php $donnees["word"] ?>" onclick="myfunc(<?php $donnees["word"] ?>)" value="<?php $donnees["word"] ?>"><br>
     <?php
     }

    ?>
    <button id="getCheckedBoxes">Get checked boxes</button>
    <script type="text/javascript">
        $(document).ready(function() {
        'use strict';
        $("#getCheckedBoxes").on('click', () => {
          $('input[type="checkbox"]').each(function(i, el){
            if($(el).is(':checked'))
     alert($(el).val())   ;  
      })
        })
    })
    </script>

And the alert message is empty,it don't show the value of checkbox chekced