input框只能输入正数

大于等于0的正数，允许小数
<input  type="number" step="1"  min="0" onkeyup="this.value= this.value.match(/\d+(\.\d{0,2})?/) ? this.value.match(/\d+(\.\d{0,2})?/)[0] : ''">

大于0的正整数
<input type="text" placeholder="输入金额" style="width: 80px;"  value="" onkeyup="if(this.value.length==1){this.value=this.value.replace(/[^1-9]/g,'')}else{this.value=this.value.replace(/\D/g,'')}" onafterpaste="if(this.value.length==1){this.value=this.value.replace(/[^1-9]/g,'')}else{this.value=this.value.replace(/\D/g,'')}"/>


转载：
https://www.cnblogs.com/chinaifae/p/10400181.html