textarea 文本框 實現右下角展現 動態字數

文本框CSS

.textarea-style{
    border:1px solid #000001;
    border-radius:5pt;
    height:60pt;
    font-size:10pt;
    margin-bottom: 2vh;
    width:100%;
    color: #000001;
    overflow-x:hidden;
    text-indent:20px
}

HTML

<textarea id="handledMsg" maxlength="200" cols="70" rows="5" class="textarea-style"
          placeholder="請輸入處理方法,不超過200字" onkeyup="setLength(this,200,'wordsLength');"></textarea>
<span id="wordsLength" style="position:absolute; right:5px; bottom:3vh;font-size:12px; color:#BDCADA">0/200</span>

JS

function setLength(obj,maxlength,id){
    var num=maxlength-obj.value.length;
    var leng=id;
    if(num<0){
        num=0;
    }
    document.getElementById(leng).innerHTML=num+"/200";
}