JS常用小代码

ENTER键可以让光标移到下一个输入框

<input onkeydown="if(event.keyCode==13)event.keyCode=9">

只能是中文

<input onkeyup="value=value.replace(/[ -~]/g,'')" onkeydown="if(event.keyCode==13)event.keyCode=9">

只能是英文和数字.屏蔽了输入法

<input style="ime-mode: disabled" onkeydown="if(event.keyCode==13)event.keyCode=9">

只能输入英文和数字

<input onkeyup="value=value.replace(/[\W]/g,'') " onbeforepaste="clipboardData.setData('text',clipboardData.getData('text').replace(/[^\d]/g,''))" onkeydown="if(event.keyCode==13)event.keyCode=9">

只能是数字

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

只能是数字,判断按键 代码如下:

<script language=javascript>
function   onlyNum()
{
    if(!((event.keyCode>=48&&event.keyCode<=57)||(event.keyCode>=96&&event.keyCode<=105)||(event.keyCode==8)))
        event.returnValue=false;
}
</script>
<input onkeydown="onlyNum();">

附:获取键盘的KeyCode

<html>
    <head>
        <script language="javascript">
            ns4 = (document.layers) ? true : false;
            ie4 = (document.all) ? true : false;
            function keyDown(e){
                if(ns4){
                    var nkey=e.which;
                    var iekey='现在是ns浏览器';
                    var realkey=String.fromCharCode(e.which);
                }
                if(ie4){
                    var iekey=event.keyCode;
                    var nkey='现在是ie浏览器';
                    var realkey=String.fromCharCode(event.keyCode);
                    if(event.keyCode==32){realkey='\' 空格\''}
                    if(event.keyCode==13){realkey='\' 回车\''}
                    if(event.keyCode==27){realkey='\' Esc\''}
                    if(event.keyCode==16){realkey='\' Shift\''}
                    if(event.keyCode==17){realkey='\' Ctrl\''}
                    if(event.keyCode==18){realkey='\' Alt\''}
                }
                alert('ns浏览器中键值:'+nkey+'\n'+'ie浏览器中键值:'+iekey+'\n'+'实际键为'+realkey);
            }
            document.onkeydown = keyDown;
            if(ns4){
                document.captureEvents(Event.KEYDOWN);
            }
        </script>
    </head>
    <body>
        //Javascript Document.
        <hr>
        <center>
            <h3>
                请按任意一个键。。。。
            </h3>
        </center>
    </body>
</html>

再加个找按键的值

<script>
function show(){
   alert("ASCII代码是:"+event.keyCode);
}
</script>
<body onkeydown="show()">

    只能是IP地址

    <html>

        <head>
            <meta http-equiv="Content-Type" content="text/html; charset=gb2312">
            <meta name="GENERATOR" content="Microsoft FrontPage 4.0">
            <meta name="ProgId" content="FrontPage.Editor.Document">
            <style>
                .a3 {
                    width: 30;
                    border: 0;
                    text-align: center
                }
            </style>
            <script>
                function mask(obj){
                    obj.value=obj.value.replace(/[^\d]/g,'')
                    key1=event.keyCode
                    if (key1==37 || key1==39){ 
                        obj.blur();
                        nextip=parseInt(obj.name.substr(2,1))
                        nextip=key1==37?nextip-1:nextip+1;
                        nextip=nextip>=5?1:nextip
                        nextip=nextip<=0?4:nextip
                        eval("ip"+nextip+".focus()")
                    } 
                    if(obj.value.length>=3) {
                        if(parseInt(obj.value)>=256 || parseInt(obj.value)<=0)
                        {
                            alert(parseInt(obj.value)+"IP地址错误!")
                            obj.value=""
                            obj.focus()
                            return false;
                        }
                        else 
                        { 
                            obj.blur();
                            nextip=parseInt(obj.name.substr(2,1))+1
                            nextip=nextip>=5?1:nextip
                            nextip=nextip<=0?4:nextip
                            eval("ip"+nextip+".focus()")
                        }
                    }
                }
                function mask_c(obj)
                {
                    clipboardData.setData('text',clipboardData.getData('text').replace(/[^\d]/g,''))
                }
            
            </script>
        <title>IP地址输入</title>

        </head>
        <body>
            IP地址输入
            <div
                style="border- 1; border-color: balck; border-style: solid;  165; font-size: 9pt">
                <input type=text name=ip1 maxlength=3 class=a3 onkeyup="mask(this)"
                    onbeforepaste=mask_c()>
                .
                <input type=text name=ip2 maxlength=3 class=a3 onkeyup="mask(this)"
                    onbeforepaste=mask_c()>
                .
                <input type=text name=ip3 maxlength=3 class=a3 onkeyup="mask(this)"
                    onbeforepaste=mask_c()>
                .
                <input type=text name=ip4 maxlength=3 class=a3 onkeyup="mask(this)"
                    onbeforepaste=mask_c()>
            </div>
        </body>

    </html>

    用#default#savehistory防止后退清空text文本框:

    <HTML>
        <HEAD>
            <META NAME="save" CONTENT="history">
            <STYLE>
                .saveHistory {
                    behavior: url(#default#savehistory);
                }
            </STYLE>
        </HEAD>
        <BODY>
            <INPUT class=saveHistory type=text id=oPersistInput>
            <input type=button
                onclick='javascript:location.href="http://www.baidu.com/"'
                value='点击进入,再按后退键试试?'>
        </BODY>
    </HTML>

    TEXTAREA自适应文字行数的多少

    <textarea rows=1 name=s1 cols=27 onpropertychange="this.style.posHeight=this.scrollHeight"> 

  上传预览图片

<img id=pic src=http://www.webjx.com/images/logo.gif>
<input type=file name=file>
<input type=button onclick=pic.src=file.value value=预览图片>
<input type=button onclick=alert(file.value) value=图片地址>
<input type=button onclick="file.outerHTML=file.outerHTML.replace(/value=\w/g,'')" value="清除file里字">

  去掉下拉选项的边框

<div style="position: absolute; left: 10px; top: 10px;  115px; height: 20px; clip: rect(2, 114, 20, 2);"> 
    <select>
     <option>cnpeople</option>
     <option>cnrose</option>
    <option>cnbruce</option>  
   </select>
   </font>
</div>

  TAB的显示

<script>
function editTab()
{
     var code, sel, tmp, r
     var tabs=""
     event.returnValue = false
     sel =event.srcElement.document.selection.createRange()
     r = event.srcElement.createTextRange()

     switch (event.keyCode)
     {
         case (8)     :
             if (!(sel.getClientRects().length > 1))
             {
                 event.returnValue = true
                 return
             }
             code = sel.text
             tmp = sel.duplicate()
             tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
             sel.setEndPoint("startToStart", tmp)
             sel.text = sel.text.replace(/^\t/gm, "")
             code = code.replace(/^\t/gm, "").replace(/\r\n/g, "\r")
             r.findText(code)
             r.select()
             break
         case (9)     :
             if (sel.getClientRects().length > 1)
             {
                 code = sel.text
                 tmp = sel.duplicate()
                 tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
                 sel.setEndPoint("startToStart", tmp)
                 sel.text = "\t"+sel.text.replace(/\r\n/g, "\r\t")
                 code = code.replace(/\r\n/g, "\r\t")
                 r.findText(code)
                 r.select()
             }
             else
             {
                 sel.text = "\t"
                 sel.select()
             }
             break
         case (13)     :
             tmp = sel.duplicate()
             tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
             tmp.setEndPoint("endToEnd", sel)

             for (var i=0; tmp.text.match(/^[\t]+/g) && i<tmp.text.match(/^[\t]+/g)[0].length; i++)     tabs += "\t"
             sel.text = "\r\n"+tabs
             sel.select()
             break
         default         :
             event.returnValue = true
             break
     }
}
</script>

<textarea cols=75 rows=20 onkeydown="editTab()">
<script>
alert("ok")
</script>
</textarea>

  文本框的上/下拉

<form name="cnbruce">
<textarea name="com">
</textarea>
</form>
<SPAN title='放大输入框' style='FONT-SIZE: 12px; CURSOR: hand'
            onclick=document.cnbruce.com.rows+=4>向下</SPAN>
<SPAN title='缩小输入框' style='FONT-SIZE: 12px; CURSOR: hand' class='arrow'
            onclick='if(document.cnbruce.com.rows>=4)document.cnbruce.com.rows-=4;else return false'>向上</SPAN>

  一个复选框,点击之后一组复选框全部都选上

<input type="checkbox" name="checkA" onpropertychange="for(i=0;i
        <A.children.length ;i++){A.children[i].checked=this.checked}">a
<br>
<span id="A">
<input type="checkbox" name="A1">
<input type="checkbox" name="A2">
<input type="checkbox" name="A3">
</span>

  Debug Textarea:在线写 js 脚本的时候,用来即时查错的东西!

<HTML>
<HEAD>
<TITLE>Debug Textarea</TITLE>
<meta http-equiv='Content-Type' content='text/html; charset=gb2312'>
</HEAD>
<style>
* {
    font-size: 12px
}

body {
    margin: 10px;
    padding: 0px
}

table.list {
    cursor: default;
    border: 1px solid #cccccc background-color :   #cccccc;
    border-collapse: collapse;
    border-Color: #cccccc;
}
</style>
<script language="javascript">
// Coded by windy_sk <windy_sk@126.com> 20040205

function reportError(msg,url,line) {
     var str = "You have found an error as below: \n\n";
     str += "Err: " + msg + " on line: " + line;
     alert(str);
     return true;
}

window.onerror = reportError;

document.onkeydown = function() {
     if(event.ctrlKey){
         switch(event.keyCode) {
             case 82: //r
                 runcode();
                 break;
             case 83: //s
                 savecode();
                 break;
             case 71: //g
                 goto(prompt('Please input the line number', '1'));
                 break;
             case 65: //a
                 document.execCommand("SelectAll");
                 break;
             case 67: //c
                 document.execCommand("Copy");
                 break;
             case 88: //x
                 document.execCommand("Cut");
                 break;
             case 86: //v
                 document.execCommand("Paste");
                 break;
             case 90: //z
                 document.execCommand("Undo");
                 break;
             case 89: //y
                 document.execCommand("Redo");
                 break;
             default:
                 break;
         }
         event.keyCode = 0;
         event.returnValue = false;
     }
     return;
}

function show_ln(){
     var txt_ln      = document.getElementById('txt_ln');
     var txt_main      = document.getElementById('txt_main');
     txt_ln.scrollTop = txt_main.scrollTop;
     while(txt_ln.scrollTop != txt_main.scrollTop) {
         txt_ln.value += (i++) + '\n';
         txt_ln.scrollTop = txt_main.scrollTop;
     }
     return;
}

function editTab(){
     var code, sel, tmp, r
     var tabs=''
     event.returnValue = false
     sel =event.srcElement.document.selection.createRange()
     r = event.srcElement.createTextRange()

     switch (event.keyCode){
         case (8)     :
             if (!(sel.getClientRects().length > 1)){
                 event.returnValue = true
                 return
             }
             code = sel.text
             tmp = sel.duplicate()
             tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
             // 出错检验代码~~~~~~
             if(sel.parentElement() != tmp.parentElement()) return;
             sel.setEndPoint('startToStart', tmp)
             sel.text = sel.text.replace(/^\t/gm, '')
             code = code.replace(/^\t/gm, '').replace(/\r\n/g, '\r')
             r.findText(code)
             r.select()
             break
         case (9)     :
             if (sel.getClientRects().length > 1){
                 code = sel.text
                 tmp = sel.duplicate()
                 tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
                 // 出错检验代码~~~~~~
                 if(sel.parentElement() != tmp.parentElement()) return;
                 sel.setEndPoint('startToStart', tmp)
                 sel.text = '\t'+sel.text.replace(/\r\n/g, '\r\t')
                 code = code.replace(/\r\n/g, '\r\t')
                 r.findText(code)
                 r.select()
             }else{
                 sel.text = '\t'
                 sel.select()
             }
             break
         case (13)     :
             tmp = sel.duplicate()
             tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)
             // 出错检验代码~~~~~~
             if(sel.parentElement() != tmp.parentElement()) return;
             tmp.setEndPoint('endToEnd', sel)
             for (var i=0; tmp.text.match(/^[\t]+/g) && i<tmp.text.match(/^[\t]+/g)[0].length; i++)     tabs += '\t'
             sel.text = '\r\n'+tabs
             sel.select()
             break
         default         :
             event.returnValue = true
             break;
     }
     return;
}

function runcode() {
     var str = document.getElementById("txt_main").value;
     var code_win = window.open('about:blank');
     code_win.document.open();
     code_win.document.writeln("<script>");
     code_win.document.writeln("function reportError(msg,url,line){\nline-=14;\nvar str='You have found an error as below: \\n\\n';\nstr+='Err: '+msg+' on line: '+(line);\nalert(str);\nopener.goto(line);\nopener.focus();\nwindow.onerror=null;\nsetTimeout('self.close()',10);\nreturn true;\n}");
     code_win.document.writeln("window.onerror = reportError;");
     code_win.document.writeln("<\/script>");
     code_win.document.writeln(str);
     code_win.document.close();
     return;
}

function savecode() {
     var str = document.getElementById("txt_main").value;
     var code_win = window.open('about:blank','_blank','top=10000');
     code_win.document.open();
     code_win.document.writeln(str);
     code_win.document.close();
     code_win.document.execCommand('saveas','','code.html');
     code_win.close();
     return;
}

function goto(ln) {
     if(!/^\d+$/.test(ln)) return;
     var obj = document.getElementById("txt_main");
     var rng = obj.createTextRange();
     var arr = obj.value.replace(/\r/, "").split(/\n/);
     if(ln>arr.length) ln = arr.length;
     var str_tmp = "";
     for(var i=0; i<ln-1; i++) {
         str_tmp += arr[i];
     }
     rng.moveStart('character',str_tmp.length+1);
     str_tmp = "";
     for(i=ln; i<arr.length; i++) {
         str_tmp += arr[i];
     }
     rng.moveEnd('character',-str_tmp.length); 
     rng.select();
     return;
}

window.onload = function() {document.getElementById("txt_main").value = "<script>\nalert(')\n<\/script>";}
</script>
<BODY>
<table width='600' class='list' border='1' bgcolor='#eeeeee'
                    bordercolorlight='#000000' bordercolordark='#FFFFFF'
                    cellpadding='0' cellspacing='0'>
   <tr bgcolor='#cccccc'> 
     <td colspan='2' height='20' align='center'>
                            <b>Debug Textarea</b>
                        </td>
   </tr>
   <tr> 
     <td colspan='2'>
         <table width='95%' border='0' align='center'>
       <tr> 
         <td align='center'>
                                        <br />
           <textarea id='txt_ln' name='content' rows='10'
                                            style=' 40px; overflow: hidden; height: 200px; border-right: 0px; text-align: right; line-height: 14px'
                                            onselectstart='this.nextSibling.focus();return false'
                                            readonly></textarea>
                                        <textarea id='txt_main' name='content' rows='10' cols='80'
                                            onkeydown='editTab()' onkeyup='show_ln()'
                                            onscroll='show_ln()' wrap='off'
                                            style='overflow: auto; height: 200px; padding-left: 5px; border-left: 0px; line-height: 14px'></textarea>
           <script>for(var i=1; i<=20; i++) document.getElementById('txt_ln').value += i + '\n';</script>
         </td>
       </tr>
           <tr> 
             <td align='center'>
                                        <br />
               <input type='button' value=' 运 行 ' onclick='runcode()'
                                            accesskey='r'>&nbsp;&nbsp;
               <input type='button' value=' 保 存 ' onclick='savecode()'
                                            accesskey='s'>&nbsp;&nbsp;
               <input type='button' value=' 跳 转 '
                                            onclick="goto(prompt('Please input the line number', '1'))"
                                            accesskey='g'>&nbsp;&nbsp;
             </td>
           </tr>
         </table>
     </td>
   </tr>
</table>
</BODY>
</HTML>

  获取input的非value值,而是显示文本值

<select name="sss"
            onChange="alert(this.options[this.selectedIndex].text)">
<option value="1">asdf</option>
<option value="2">bbbb</option>
<option value="3">ccc</option>
</select>

  select里的option进行分类列表

<span style="position: absolute; border: 1px inset #d3d6d9"><select
                style="margin: -2px;  200px">
<option selected>------------请选择------------</option>
<optgroup label="JavaScript&VBScript区">
<option>原    创
<option>经    典
<optgroup label="后台区">
<option>asp&sql
<option>php&mysql

            </select>
        </span>

  动态添加

<form name="myForm" method="post">
<select name="dept_company" size="10" multiple id="dept_company"
                class="mySelect">
           <option value="">Please Select...</option>
           <option value="a">AA</option>
           <option value="b">BB</option>
           <option value="c">CC</option>
         </select>
            <input name="dept_company_list" type="hidden">
         <input name="button" type="button" class="myButton"
                onClick="addItem('dept_company','dept_company2')"
                value="添加--&gt;&gt;">
         <input name="button" type="button" class="myButton"
                onClick="deleteItem('dept_company2','dept_company')"
                value="&lt;&lt;--删除">
         <select name="dept_company2" size="10" multiple
                id="dept_company2" class="mySelect">
         </select>
</form>
<script>
function addItem(fromName,toName){
     eval("var obj1=myForm."+fromName);
     eval("var obj2=myForm."+toName);
     obj1.options[0].selected=false;
     if(obj1.selectedIndex == -1)
         return false;
     var tempValue;
     var tempText;
     for(var i=1;i<obj1.length;i++){ //begin from 1
         if(obj1.selectedIndex == -1)break;
         tempValue=obj1.options[obj1.selectedIndex].value;
         tempText=obj1.options[obj1.selectedIndex].text;
         obj1.options[obj1.selectedIndex]=null;
         obj2.add(new Option(tempText,tempValue),0); 
     }
}
function deleteItem(fromName,toName){
     eval("var obj1=myForm."+fromName);
     eval("var obj2=myForm."+toName);
     if(obj1.selectedIndex == -1)
         return false;
     var tempValue;
     var tempText;
     for(var i=0;i<obj1.length;i++){ //begin from 0
         if(obj1.selectedIndex == -1)break;
         tempValue=obj1.options[obj1.selectedIndex].value;
         tempText=obj1.options[obj1.selectedIndex].text;
         obj1.options[obj1.selectedIndex]=null;
         obj2.add(new Option(tempText,tempValue),1); //addItem index is 1
     }
}
</script>

  提示限制输入的字符数

<script language="JavaScript">
<!--

function SymError()
{
   return true;
}

window.onerror = SymError;

function strlength(str){
     var l=str.length;
     var n=l
     for (var i=0;i<l;i++)
     {
         if (str.charCodeAt(i)<0||str.charCodeAt(i)>255) n++
     }
     return n        
}

function changebyte(value,length){
     var l=strlength(value)
     if (l<=length) {
         if (document.all!=null) document.all("byte").innerText="还可以输入"+(length-l)+"字节"
     }
     else
     {
         document.all("byte").innerText="输入字节数超出范围"
     }
     return true
}

function changebyte1(value,length){
     var l=strlength(value)
     if (l<=length) {
         if (document.all!=null) document.all("byte1").innerText="还可以输入"+(length-l)+"字节"
     }
     else
     {
         document.all("byte1").innerText="输入字节数超出范围"
     }
     return true
}

function changebyte2(value,length){
     var l=strlength(value)
     if (l<=length) {
         if (document.all!=null) document.all("byte2").innerText="还可以输入"+(length-l)+"字节"
     }
     else
     {
         document.all("byte2").innerText="输入字节数超出范围"
     }
     return true
}
</script>
<form method="post" name=test onSubmit="return checkdata()" action="">
<TEXTAREA
                onkeydown="return changebyte1(document.test.icqcontent.value,198)"
                onkeyup="return changebyte1(document.test.icqcontent.value,198)"
                name=icqcontent cols=40 rows="3"></TEXTAREA>
<SPAN id=byte1><SCRIPT language=JavaScript>changebyte1(document.test.icqcontent.value,198);</SCRIPT>
            </SPAN>
</form>

  判断填写字数的限制

<script language=javascript>
function gbcount(message,total,used,remain)
{
   var max;
   max = total.value;
   if(message.value.length > max){
     message.value = message.value.substring(0,max);
     used.value = max;
     remain.value = 0;
     alert('留言不能超过规定的字数!');
   }
   else{
     used.value = message.value.length;
     remain.value = max - used.value;
   }
}
</script>

<form name='myform'>
<textarea name='GuestContent' cols='59' rows='6'
                onkeydown=gbcount(this.form.GuestContent,this.form.total,this.form.used,this.form.remain);
                onkeyup=gbcount(this.form.GuestContent,this.form.total,this.form.used,this.form.remain);></textarea>
最多字数:<INPUT disabled maxLength=4 name=total size=3 value=20>
已用字数:<INPUT disabled maxLength=4 name=used size=3 value=0>
剩余字数:<INPUT disabled maxLength=4 name=remain size=3>
</form>
原文地址:https://www.cnblogs.com/rocker/p/1661536.html