目录:1:js字符串长度限制、判断字符长度、js限制输入、限制不能输入、textarea长度限制2.:js判断汉字、判断是否汉字、只能输入汉字3:js判断是否输入英文、只能输入英文4:js只能输入数字,判断数字、验证数字、检测数字、判断是否为数字、只能输入数字5:只能输入英文字符和数字6:jsemail验证、js判断email、信箱/邮箱格式验证7:js字符过滤,屏蔽关键字8:js密码验证、判断密码2.1:js不为空、为空或不是对象、判断为空、判断不为空2.2:比较两个表单项的值是否相同2.3:表单只能为数字和"_",2.4:表单项输入数值/长度限定2.5:中文/英文/数字/邮件地址合法性判断2.6:限定表单项不能输入的字符2.7表单的自符控制2.8:form文本域的通用校验函数1.长度限制<script>functiontest(){if(document.a.b.value.length>50){alert("不能超过50个字符！");document.a.b.focus();returnfalse;}}</script><formname=aonsubmit="returntest()"><textareaname="b"cols="40"wrap="VIRTUAL"rows="6"></textarea><inputtype="submit"name="Submit"value="check"></form>2.只能是汉字<inputonkeyup="value="/oblog/value.replace(/[^\u4E00-\u9FA5]/g,'')">3."只能是英文<scriptlanguage=javascript>functiononlyEng(){if(!(event.keyCode>=65&&event.keyCode<=90))event.returnvalue=false;}</script><inputonkeydown="onlyEng();">4.只能是数字<scriptlanguage=javascript>functiononlyNum(){if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)))//考虑小键盘上的数字键event.returnvalue=false;}</script><inputonkeydown="onlyNum();">5.只能是英文字符和数字<inputonkeyup="value="/oblog/value.replace(/[\W]/g,"'')"onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^\d]/g,''))">6.验证油箱格式<SCRIPTLANGUAGE=javascriptRUNAT=Server>functionisEmail(strEmail){if(strEmail.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/)!=-1)returntrue;elsealert("oh");}</SCRIPT><inputtype=textonblur=isEmail(this.value)>7.屏蔽关键字(这里屏蔽***和****)<scriptlanguage="javascript1.2">functiontest(){if((a.b.value.indexOf("***")==0)||(a.b.value.indexOf("****")==0)){alert(":)");a.b.focus();returnfalse;}}</script><formname=aonsubmit="returntest()"><inputtype=textname=b><inputtype="submit"name="Submit"value="check"></form>8.两次输入密码是否相同<FORMMETHOD=POSTACTION=""><inputtype="password"id="input1"><inputtype="password"id="input2"><inputtype="button"value="test"onclick="check()"></FORM><script>functioncheck(){with(document.all){if(input1.value!=input2.va