如何在输入代码中使用javascript显示实时输入？

Question

How can I make this script run by replacing textarea tag with input tag? I used input tag in my page and wanna add this code but this code used textarea. if I change textarea to input the code doesn't work.

 function setFontText(text) { document.getElementById("Courier_new").innerHTML = text; document.getElementById("Arial_Black").innerHTML = text; } 

 <textarea id="textField0" autocomplete="off" style="font-family:'Alex Brush';" onkeyup="javascript:setFontText(this.value);" rows="2" name="textField0"></textarea> Multiple text area: <textarea id="Courier_new" class="fontTextArea2" style="font-family:Courier;" autocomplete="off" name="Courier new"></textarea> <textarea id="Arial_Black" class="fontTextArea2" style="font-family:Arial; " autocomplete="off" name="Arial Black"></textarea> 

Answer 1

Try this:-

function setFontText(text) {
  document.getElementById("Courier_new").value = text;
  document.getElementById("Arial_Black").value = text;
}

Or, Using document.getElementsByClassName

The method .getElementsByClassName() returns an array-like object of elements.so you have to access first element (if there is any).

var elements = document.getElementsByClassName("anyclass);
var value = elements[0].value;

alert(value); // 1

or, you could also use the .querySelector() method:

var value = document.querySelector('.anyclass').value;
alert(value); // 1

Answer 2

Update:

Register the function:

function setFontText(text) {
  document.getElementById("Courier_new").innerHTML = text;
  document.getElementById("Arial_Black").innerHTML = text;
}

Call the function with a string as parameter.

setFontText("TEXT");

it works fine with textarea as well. Syntax would be like this. Here for the input field in stackoverflow:

var x = document.getElementById("wmd-input") x.innerText = "TEXTFIELDINPUT"

or

x.innerHTML = "TEXTFIELDINPUT"*