限定文本框输入为数值

Question

用JS怎么写，高手指教

Answer 1

<input type="text"  value='' onkeyup='this.value=this.value.replace(/[^0-9]/,"")' />

Answer 2

<input type="text"  value='' onkeyup='this.value=this.value.substring(0,n)' />

Answer 3

<input type="text" onkeyup='this.value=this.value.replace(/[^0-9.]/gi,"")' onafterpaste='this.value=this.value.replace(/[^0-9.]/gi,"")'>

Answer 4

onkeyup='this.value=this.value.replace(/[^0-9]/,"")

Answer 5

<input type=text onblur="if(!parseFloat(this.value)){alert('你输入的不是数字！');this.focus();this.select();}else{this.value=parseFloat(this.value);}">