HTML object: introduction to some object properties of html

不言
Release: 2018-08-09 15:16:44
Original
2576 people have browsed it

The content of this article is about HTML objects: an introduction to some object attributes of html, which has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Form object

Form object method

reset(): Resets all input elements of the form to their default values.

submit(): Submit the form.

Text object

Text object property

disabled: Sets or returns whether the text field should be disabled.

readOnly: Sets or returns whether the text field should be read-only.

value: Set or return the value of the value attribute of the text field.

Text object method

focus(): Set focus on the text field.

Example

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <form>
            <input name = "wd" />
            <input type="submit" value="百度一下" onclick="sub()">
        </form>
        <script>
            var form = document.getElementsByTagName("form")[0];
            var text = document.getElementsByName("wd")[0];
            text.focus();
            function sub(){
                var text = document.getElementsByName("wd")[0];
//              text.value = "魔道";
//              text.readOnly = "true";
//              console.log(text.readOnly);
//              text.disabled = "true";
                console.log(text.disabled);
                text.focus();
            }
            //type为text、password、textarea的标签均有value、focus、disabled、readOnly
        </script>
    </body>
</html>
Copy after login

Radio object

Radio object property

checked: Sets or returns the status of the radio button.

disabled: Sets or returns whether the radio button is disabled.

value: Sets or returns the value of the radio button's value attribute.

Checkbox object

Checkbox object property

checked: Sets or returns whether the checkbox should be checked.

disabled : Sets or returns whether the checkbox should be disabled.

value: Set or return the value of the value attribute of the checkbox

Select object

Select object collection

options[]: Returns an array containing all options in the drop-down list.

Select object property

disabled: Sets or returns whether the drop-down list should be disabled.

length: Returns the number of options in the drop-down list.

selectedIndex: Set or return the index number of the selected item in the drop-down list.

Select object method

add(): Add an option to the drop-down list.

remove(): Remove an option from the drop-down list.

Option object

Option object construction method

Option(text,value): Create an Option object through text and value values

Option Object Attribute

selected: Set or return the value of the selected attribute.

text: Sets or returns the plain text value of an option.

value: Set or return the value sent to the server.

Select object and Option object example

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <select id="grade">
            <option  value="1">一年级</option>
            <option  value="2">二年级</option>
            <option  value="3">三年级</option>
            <option  value="4">四年级</option>
        </select>
        <input type="button" onclick="text()" value="按钮" />
        <script type="text/javascript">
            function text(){
                var select = document.getElementById("grade");
                console.log(select.disabled);
                console.log(select.length);
                console.log(select.selectedIndex);

                console.log("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`")

                var options = select.options;
                console.log(options[select.selectedIndex].value);

                console.log("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@")

                for(var i=0;i<options.length;i++){
                    console.log(options[i].value);
                    console.log(options[i].selected);
                    console.log(options[i].text);
                }

                var option = new Option("五年级","5");
                select.add(option);
                select.remove(0);
            }   
        </script>
    </body>
</html>
Copy after login

Registry

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title></title>
    </head>
    <body>
        <span style="color:red;" id="wrong-massage"></span><br />
        <form onsubmit="return check()">
            <table>
                <tr>
                    <td>用户名:</td>
                    <td><input id="name"  placeholder="请输入用户名" onblur="check_name()" ></td>
                </tr>
                <tr>
                    <td>密码:</td>
                    <td><input id="pw" type="password" placeholder="请输入密码" onblur="check_pw()"></td>
                </tr>
                <tr>
                    <td>确认密码:</td>
                    <td><input id="pw-check" type="password" placeholder="请输入确认密码"/></td>
                </tr>
            </table>
            <input type="radio" name="sex" value="0"/>男
            <input type="radio" name="sex" value="1"/>女
            <br />
            <input type="checkbox" name="hobby" value="0"/>羽毛球
            <input type="checkbox" name="hobby" value="1"/>篮球
            <input type="checkbox" name="hobby" value="2"/>乒乓球
            <input type="checkbox" name="hobby" value="3"/>足球
            <br />
            <select id="grade">
                <option value="1">大一</option>
                <option value="2">大二</option>
                <option value="3">大三</option>
                <option value="4">大四</option>
            </select>
            <br />
            <td><input type="reset" value="重置" /></td>
            <td><input type="submit" value="注册"/></td>
        </form>
        <script>
            //使用$()函数可节省代码量
            function $(id){
                return document.getElementById(id);
            }

            function check(){
                var n = document.getElementById("name");
                var w = document.getElementById("pw");
                var msg = document.getElementById("wrong-massage");
                var c = document.getElementById("pw-check");

                if(n.value.length>12){
                    msg.innerHTML = "用户名不能超过15个字符,请重新输入!";
                    n.focus();
                    return false;
                }
                if(n.value.length==0){
                    msg.innerHTML = "用户名不能为空,请重新输入!";
                    n.focus();
                    return false;
                }
                if(w.value.length>12){
                    msg.innerHTML = "密码不能超过12个字符,请重新输入!";
                    w.focus();
                    return false;
                }
                if(w.value.length==0){
                    msg.innerHTML = "密码不能为空,请重新输入!";
                    w.focus();
                    return false;
                }
                if(w.value!=c.value){
                    msg.innerHTML = "密码错误,请重新输入!";
                    c.focus();
                    return false;
                }

                var sex = document.getElementsByName("sex");
                var hobby = document.getElementsByName("hobby");
                for(var i=0;i<sex.length;i++){
                    sex[i].disabled=true;
                    console.log(sex[i].checked+" "+sex[i].value);
                }

                console.log("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")

                for(var i=0;i<hobby.length;i++){
                    hobby[i].checked = true;
                    console.log(hobby[i].checked+" "+hobby[i].value);
                }

                console.log("~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~")


                var select = document.getElementById("grade");
                var options = select.options;
                console.log(select.length);
                console.log(select.selectedIndex);
                console.log(options[select.selectedIndex].value);
                for(var i=0;i<options.length;i++){
                    var option = options[i];
                    console.log(option.value)
                    select.disabled = true;
                }
                return false;
            }

            function check_name(){
                var n = document.getElementById("name");
                var msg = document.getElementById("wrong-massage");

                if(n.value.length>12){
                    msg.innerHTML = "用户名不能超过15个字符,请重新输入!";
                    n.value = "";
                    n.focus();
                }
                else if(n.value.length==0){
                    msg.innerHTML = "用户名不能为空,请重新输入!";
                    n.focus();
                }
                else{
                    msg.innerHTML = " ";
                }
            }
            function check_pw(){
                var w = document.getElementById("pw");
                var msg = document.getElementById("wrong-massage");

                if(w.value.length>12){
                    msg.innerHTML = "密码不能超过12个字符,请重新输入!";
                    w.value = "";
                    w.focus();
                }
                else if(w.value.length==0){
                    msg.innerHTML = "密码不匹配,请重新输入!";
                    w.focus();
                }
                else
                {
                    msg.innerHTML = " ";
                }
            }
        </script>
    </body>
</html>
Copy after login

Image object

Image object properties

src: Set or return the URL of the image.

related suggestion:




The above is the detailed content of HTML object: introduction to some object properties of html. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!