如何将value =“”添加到输入

Question

Is there a possibility to add the value tag to an input with javascript?

eg to change a input fild in a form from:

<input type="text" name="mail" id="mail">

to:

<input type="text" name="mail" id="mail" value="<?php echo $_SESSION['email'] ?>

EDIT:

<?php
echo '
<script type="text/javascript">

document.getElementById("mail").setAttribute("value", "<?php echo $_SESSION["email"];?>");

</script>';
?>

Answer 1

是的，您可以使用javascript访问输入的值字段

document.getElementById('mail').value = "someemail@email.com";

Answer 2

Use setAttribute() to fill in the attribute of an element.

 document.getElementById("mail").setAttribute("value", "<?php echo $_SESSION['email'];?>"); 

 <input type="text" name="mail" id="mail"> 

You can't use <?php inside a PHP string. Use concatenation instead.

<?php
echo '
<script type="text/javascript">

document.getElementById("mail").setAttribute("value", "' . $_SESSION["email"] . '");

</script>';
?>

Answer 3

Not sure what you are trying to achieve but you could save PHP value as a JS variable and go from there. Something like this?

var email = '<?php echo $_SESSION['email'];?>';
document.getElementById('mail').value = email;

Answer 4

Using the method echo , returning the element input.

$youvalue = "This is the value of the input"
echo '<input type="text" name="mail" id="mail" value="'.$yourvalue.'">';

Using the method echo again, returning a script.

$youvalue = "This is the value of the input"
echo '<script>var x = document.createElement("input");x.type = "text";x.name = "mail";x.id = "mail";x.value = "'.$youvalue.'"; document.body.appendChild(x);</script>'