正则表达式

只能输入纯数字

onkeyup="this.value=this.value.replace(/D/g,'')";
onafterpaste="this.value=this.value.replace(/D/g,'')";

只能输入中文
 onkeyup="value=value.replace(/[^u4E00-u9FA5]/g,'')" ;onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^u4E00-u9FA5]/g,''))"
开头不能为0,不能有小数点 
onkeyup="this.value=this.value.replace(/D|^0/g,'')" onafterpaste="this.value=this.value.replace(/D|^0/g,'')"
开头不能为0
<div class="input-choseNum">
<input type="number" id="inp-chooseNum" oninput='this.value=this.value.replace(/^[0]+[0-9]*$/gi,"")' maxlength="5" />
<span class="sureChoose">确定</span><span class="closeChoose">取消</span>
</div>
原文地址:https://www.cnblogs.com/deepalley/p/13215677.html