按Tab，空格，删除和退格键时如何计算字符？

Question

I know this question may be a duplicate but I wasn't able to find a solution so far. Maybe the way I searched is wrong.

I need to count the total characters of textarea along with spaces using "space key" "tab key" "delete" or "backspace".

So far I have the below code but I don't know why it is not considering tab space in the count.

<textarea id="myTextArae"></textarea>

$("#myTextArae").on("keydown", function(e) {
  if (e.keyCode === 9) { // tab was pressed
    let start = this.selectionStart;
    let end = this.selectionEnd;
    var $this = $(this);
    $this.val($this.val().substring(0, start) + "\t" + $this.val().substring(end));
    this.selectionStart = this.selectionEnd = start + 1;
    var txt = $("#balanceCharacInTxtarea").val();
    if (txt != parseInt("0")) {
      e.preventDefault();
    }
    return false;
  }
})

$("#myTextArea").on("paste", function (e) {
  setTimeout(function () {
    that.check(e, e1, 0);
  }, 100);
});

check(eventcode, e1, code) {
  if (code === 0) {
    this.calculate = this.characterCount(e, e1, default);
  } if (code === 1) {
    this.calculate = e1 ? e1.length : 0;
  }
}
var default = 175

Answer 1

How about something as easy as

 $("#yourtextarea").keyup(function() {
    var count = $("#yourtextarea").val().length;
 });

This will count spaces, tabs, newlines and other characters.
It will trigger on paste as well.

Example :

 $(document).ready(function(){ $("#test").html(0); //this is for counting the characters $("#message").keyup(function() { var txtlgt = $("#message").val().length; $("#test").html(txtlgt); }); //This is for enabling tabs in the textarea $("#message").on("keydown", function(e) { if (e.keyCode === 9){ let start = this.selectionStart; let end = this.selectionEnd; var $this = $(this); $this.val($this.val().substring(0, start) + "\\t" + $this.val().substring(end)); this.selectionStart = this.selectionEnd = start + 1; return false; } }) }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div id="test"></div> <textarea id="message"></textarea>