function numCheck(obj){
        //如果輸入非數(shù)字，則替換為''，如果輸入數(shù)字，
        if($(obj).val() != '') {
        $(obj).val($(obj).val().replace(/[^\d]/g, ''));
        }
}

html

<input maxlength='11' onkeyup='numCheck(this)' autocomplete='off' type='text' id='orgvalue'
placeholder='默認值'>

正則數(shù)字轉(zhuǎn)化為大寫

        function smalltoBIG(n){    
          var fraction = ['角', '分'];    
          var digit = ['零', '壹', '貳', '叁', '肆', '伍', '陸', '柒', '捌', '玖'];    
          var unit = [ ['元', '萬', '億'], ['', '拾', '佰', '仟']  ];    
          var head = n < 0? '欠': '';    
          n = Math.abs(n); var s = ''; for (var i = 0; i < fraction.length; i++)     
        {    
          s += (digit[Math.floor(n * 10 * Math.pow(10, i)) % 10] + fraction[i]).replace(/零./, '');    
        }    
          s = s || '整';    
          n = Math.floor(n); for (var i = 0; i < unit[0].length && n > 0; i++)     
        {    
          var p = '';    
          for (var j = 0; j < unit[1].length && n > 0; j++)     
        {    
            p = digit[n % 10] + unit[1][j] + p;    
            n = Math.floor(n / 10);    
        }    
            s = p.replace(/(零.)*零$/, '').replace(/^$/, '零')  + unit[0][i] + s;    
        }    
           return head + s.replace(/(零.)*零元/, '元').replace(/(零.)+/g, '零').replace(/^整$/, '零元整');    
        } 

校驗小數(shù)點后留取幾位小數(shù)

         $(".moneyText").keyup(function(){

      var reg = /^\d+\.?(\d{1,2})?$/;
      while (!reg.test($(this).val()) && $(this).val() != "") {
          $(this).val(checkStr($(this).val()));
      }
        });

      //檢查是否符合金額格式:只能輸入數(shù)字且最多保留小數(shù)點后兩位
    function checkStr(str) {
        str = str.substring(0,str.length-1);
        return str;
    }

限制textarea最多輸入長度顯示

  </body>
  <textarea onkeyup="checkLen(this)"></textarea>
  <div>您還可以輸入 <span id="count">300</span> 個文字</div>

  <script type="text/javascript">
    function checkLen(obj)
        {
            var maxChars = 300;//最多字符數(shù)
                  if (obj.value.length > maxChars)
                  obj.value = obj.value.substring(0,maxChars);
                  var curr = maxChars - obj.value.length;
          document.getElementById("count").innerHTML = curr.toString();
        }
    </script>

正則校驗如果輸入回車或者空格替換成<br>

    var Explain =  $('#charDetail-box').text().replace(/[\r\n]/g,'<br>');
    $('#charDetail-box').html(Explain);