How to use javascript to calculate how many characters can be entered in the text box_Basic knowledge

The code below is super simple, I won’t say much more, just go to the code.

//输入计数

//count：能輸入的數據總量
  function Calculation(v, count) {
    var span = $(v).next();
    var valLength = $(v).val().length;
    if (valLength > count) {
      $(v).val($(v).val().substr(0, count));
      valLength = count;
    }
    span.text("您已輸入" + valLength + "字元,還剩下" + (count - valLength) + "字元");
  }

The above code uses JavaScript to calculate how many characters can be entered into the text box. I hope you like it.