用正则表达式限制文本框的输入

最新推荐文章于 2021-11-12 11:24:35 发布

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最新推荐文章于 2021-11-12 11:24:35 发布

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分类专栏： JAVA 文章标签： java

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本文深入探讨了如何通过JavaScript实现输入验证，限制用户仅能输入数字、字母、小数点，并详细介绍了不同场景下的代码实现，包括数字与小数点的输入限制、特定字符的排除以及限制输入到指定技术领域的实例。从基本的数字和字母输入限制到更复杂的条件验证，涵盖了前端开发、后端开发、移动开发等多个技术领域，旨在为开发者提供全面的输入管理解决方案。

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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; }