Re-posting <input> value into <textarea>

问题

I want to re-generate user's input values onto textarea with specific format. I've created input and 'select' with various 'options' inside as well as 'button' that triggers the function.

Can someone please tell me what I'm doing wrong here..?

<SCRIPT>

function myFunction() {
   var finaL = document.getElementById("textArea").value;
   var spacE = " | ";

   var a = document.getElementById("input1").value;
   var b = document.getElementById("input2").value;
   var c = document.getElementById("selecT").value;

   finaL = a + spacE + b + spacE + c;
}

</SCRIPT>

回答1:

In your code your are getting the value of the textarea and storing it in final variable which is just a string. What you need to do is get the reference of the textarea in the final variable and then set the value.

Working Code:

function myFunction() {
    var finaL = document.getElementById("textArea");
    var spacE = " | ";
    var a = document.getElementById("input1").value;
    var b = document.getElementById("input2").value;
    var c = document.getElementById("selecT").value;
    finaL.value = a + spacE + b + spacE + c;
}

<label for="input1">Male</label>
<input name="input1" id="input1" /> <br>
<label for="input2">Input 3</label>
<input name="input2" id="input2" /> <br>
<label for="selecT">Input 3</label>
<select id="selecT">
    <option value="Value 1">Value 1</option>
    <option value="Value 2">Value 2</option>
    <option value="Value 3">Value 3</option>
</select>
<br>
<button type="button" onclick="myFunction()">Copy</button>
<br>
<label>Result</label>
<textarea id="textArea"></textarea>

回答2:

just update code to this

<SCRIPT>

function myFunction() {
   var finaL = document.getElementById("textArea").value;
   var spacE = " | ";

   var a = document.getElementById("input1").value;
   var b = document.getElementById("input2").value;
   var c = document.getElementById("selecT").value;

   document.getElementById("textArea").value = a + spacE + b + spacE + c;
}

</SCRIPT>

what i change is from this

value = a + spacE + b + spacE + c;

to this

document.getElementById("textArea").value = a + spacE + b + spacE + c;

来源：https://stackoverflow.com/questions/59674766/re-posting-input-value-into-textarea