用正则表达式限制文本框的输入

1.文本框只能输入数字代码(小数点也不能输入)

代码:

<input onkeyup="this.value=this.value.replace(/\D/g,'''')" onafterpaste="this.value=this.value.replace(/\D/g,'''')">

2.只能输入数字,能输小数点.

代码:

<input onkeyup="if(isNaN(value))execCommand(''undo'')" onafterpaste="if(isNaN(value))execCommand(''undo'')">
<input name=txt1 onchange="if(/\D/.test(this.value)){alert(''只能输入数字'');this.value='''';}">

3.数字和小数点方法二

代码:

<input type=text tvalue="" ovalue="" onkeypress="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.tvalue=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.ovalue=this.value" onkeyup="if(!this.value.match(/^[\+\-]?\d*?\.?\d*?$/))this.value=this.t_value;else this.tvalue=this.value;if(this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/))this.ovalue=this.value" onblur="if(!this.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))this.value=this.o_value;else{if(this.value.match(/^\.\d+$/))this.value=0+this.value;if(this.value.match(/^\.$/))this.value=0;this.ovalue=this.value}">

4.只能输入字母和汉字

代码:

<input onkeyup="value=value.replace(/[\d]/g,'''') "onbeforepaste="clipboardData.setData(''text'',clipboardData.getData(''text'').replace(/[\d]/g,''''))" maxlength=10 name="Numbers">

5.只能输入英文字母和数字,不能输入中文

代码:

<input onkeyup="value=value.replace(/[^\w\.\/]/ig,'''')">

6.只能输入数字和英文

代码:

<font color="Red">chun</font>
<input onKeyUp="value=value.replace(/[^\d|chun]/g,'''')">

7.小数点后只能有最多两位(数字,中文都可输入),不能输入字母和运算符号:

代码:

<input onKeyPress="if((event.keyCode<48 || event.keyCode>57) && event.keyCode!=46 || /\.\d\d$/.test(value))event.returnValue=false">

8.小数点后只能有最多两位(数字,字母,中文都可输入),可以输入运算符号:

代码:

<input onkeyup="this.value=this.value.replace(/^(\-)*(\d+)\.(\d\d).*$/,''$1$2.$3'')">

9.限制只准输入数字和字母

function permitInputNumericAlpha(theField,e) {  
   var keynumvar;
   var keycharvar;
   var numcheck;
   if(window.event){
    //for ie
    keynum = e.keyCode
   }else if(e.which) {
    // Netscape/Firefox/Opera
    keynum = e.which
   }

   if(keynum == 39 || keynum == 37 || keynum == 96)
   {
    //    
     return false;
   }  
   if( keynum == '0x60'
    || keynum == '0x61'
    || keynum == '0x62'
    || keynum == '0x63'
    || keynum == '0x64'
    || keynum == '0x65'
    || keynum == '0x66'
    || keynum == '0x67'
    || keynum == '0x68'
    || keynum == '0x69'
    || (keynum > 47 && keynum < 58)
    || (keynum > 64 && keynum < 91)
    || (keynum > 96 && keynum < 123)
   ){
    //0~9 and alpha
    return true;
   }
   if(keynum == '0x8'){
    //Backspace key
    return true;
   }
   if(keynum == '0x25' || keynum == '0x27'){
    //LEFT or RIGHT ARROW key
    return true;
   }
  
   return false;  
}
  

10.限制只准输入数字和小数点
function permitInputDecimal(theField,e) {  
   var keynumvar;
   var keycharvar;
   var numcheck;
   if(window.event){
    //for ie
    keynum = e.keyCode
   }else if(e.which) {
    // Netscape/Firefox/Opera
    keynum = e.which
   }  
   if( keynum == '0x60'
    || keynum == '0x61'
    || keynum == '0x62'
    || keynum == '0x63'
    || keynum == '0x64'
    || keynum == '0x65'
    || keynum == '0x66'
    || keynum == '0x67'
    || keynum == '0x68'
    || keynum == '0x69'
    || keynum == '48'
    || keynum == '49'
    || keynum == '50'
    || keynum == '51'
    || keynum == '52'
    || keynum == '53'
    || keynum == '54'
    || keynum == '55'
    || keynum == '56'
    || keynum == '57'
   ){
    //0~9
    return true;
   }
   if(keynum == '0x8'){
    //Backspace key
    return true;
   }
  
   if(keynum == '0x9'){
    //Tab key  
   return true;
   }

   if(keynum == '0x6E'){
    //DECIMAL POINT (.) key
    var theValue = document.getElementById(theField).value;   
    if(theValue != "" && theValue.indexOf(".")==-1){  
     return true;    
    }   
   }
   if(keynum == '0x25' || keynum == '0x27'){
    //LEFT or RIGHT ARROW key (-->) (<--)
    return true;
   }
   return false;  
}