https://www.cnblogs.com/littledonkey/p/9481782.htmlhtml
1.只能輸入英文this
<input type="text" onkeyup="value=value.replace(/[^a-zA-Z]/g,'')">3d
<input type="text" onkeyup="value=value.replace(/[^\a-\z\A-\Z]/g,'')" onkeydown="fncKeyStop(event)" onpaste="return false" oncontextmenu="return false" />htm
3.只能輸入數字:blog
<input onkeyup="this.value=this.value.replace(/\D/g,'')" onafterpaste="this.value=this.value.replace(/\D/g,'')">input