printing users input into an input field using php - php

Question

how can I get users input and print it into another text field input?
I'm using php. I have 2 input types of text and one submit button. i want to be able to print the results of input A into the input textbox B
example:
<form>
<input type="text" name="input"/> <!-- thiss is where the user enters text -->
<input type="text" name="output"/> <!-- I take that text out and output it here -->
<input type="submit" value="submit" <?php echo $input;/>
</form>
I keep trying to echo "$input" into output but not working.

Answer 1

hope this will help
<?php
$output= (isset($_POST['submit']))?$_POST['input']:'';
?>
pure php. <br>
try to input value in input field then submit.
<form method="post">
<input type="text" name="input"/> <!-- thiss is where the user enters text -->
<input type="text" name="output" value="<?php echo $output;?>"/> <!-- I take that text out and output it here -->
<input type="submit" name="submit" value="submit">
</form>
using javascript onchange.<br>try to input value in field input1
<form method="post">
<input type="text" id="input1" name="input1" onchange="clone();"/> <!-- thiss is where the user enters text -->
<input type="text" id="output1" name="output1" /> <!-- I take that text out and output it here -->
<input type="submit" name="submit1" value="submit">
</form>
<script>
function clone()
{
var x = document.getElementById("input1").value; document.getElementById("output1").value=x;
}
</script>

Answer 2

You cannot do this with PHP since PHP is a server side language. It does not support client side manipulation.
You will need something like this.
<script type="text/javascript">
$(document).ready(function () {
$(document).on('change', 'input[name="input"]', function () {
var contents = $(this).val();
$('input[name="outut"]').val(contents);
})
});
</script>
<!-- HTML -->
<form method="post">
<input type="text" name="input" />
<input type="text" name="output" value="" />
<input type="submit" name="submit" value="submit">
</form>
For more information about jQuery take a look at this W3Schools article

Answer 3

May be this what you are looking for using simple javascript events
function myFunction(){
var a=document.getElementById('a').value;
document.getElementById('b').value= a
}
<form>
<input type="text" name="input" onkeydown="myFunction()" onkeydown="myFunction()" id="a"/> <!-- thiss is where the user enters text -->
<input type="text" name="output" id ="b"/> <!-- I take that text out and output it here -->
<input type="submit" value="submit" >
</form>