当字段值为空时，表示为'；它太短了！（Javascript）_Javascript_Html_Validation

当字段值为空时，表示为'；它太短了！（Javascript）

javascript html validation

当字段值为空时，表示为'；它太短了！（Javascript）,javascript,html,validation,Javascript,Html,Validation,我会尽我所能解释清楚。好的，这是我的代码： function validation() { var name = document.getElementById("name").value; var email = document.getElementById("email").value; var subject = document.getElementById("subject").value; var message = document.getEle

我会尽我所能解释清楚。好的，这是我的代码：

function validation() {

    var name = document.getElementById("name").value;
    var email = document.getElementById("email").value;
    var subject = document.getElementById("subject").value;
    var message = document.getElementById("message").value;
    var at = "@";
    var dot = ".";
    var lat = email.indexOf(at);
    var lstr = email.length;
    var ldot = email.indexOf(dot);

    var success = true;

    if (name == null || name == "") {
        success = false;
        document.getElementById("name-error").innerHTML = "I want to know who you are!";
    }

    if (document.contact.name.value.length <= 5) {
        success = false;
        document.getElementById("name-error").innerHTML = "Full name, please!";
    }

    if (email.indexOf(at) == -1 || email.indexOf(at) == 0 || email.indexOf(at) == lstr) {
        success = false;
        document.getElementById("email-error").innerHTML = "That's not an email!";
    }

    if (email == null || email == "") {
        success = false;
        document.getElementById("email-error").innerHTML = "Give me your email!";
    }

    if (document.contact.email.value.length <= 8) {
        success = false;
        document.getElementById("email-error").innerHTML = "Email is too short!";
    }

    if (subject == null || subject == "") {
        success = false;
        document.getElementById("subject-error").innerHTML = "I need a subject!";
    }

    if (document.contact.subject.value.length <= 5) {
        success = false;
        document.getElementById("subject-error").innerHTML = "A longer subject would be nice.";
    }

    if (message == null || message == "") {
        success = false;
        document.getElementById("message-error").innerHTML = "Don't forget your message!";
    }

    if (document.contact.message.value.length <= 30) {
        success = false;
        document.getElementById("message-error").innerHTML = "Your message is too concise!";
    }

    return success;

}

函数验证（）{
var name=document.getElementById（“name”）.value；
var email=document.getElementById（“email”）.value；
var subject=document.getElementById（“subject”）.value；
var message=document.getElementById（“message”）.value；
var at=“@”；
var dot=“.”；
var lat=email.indexOf（at）；
var lstr=email.length；
var ldot=email.indexOf（dot）；
var成功=真；
如果（名称==null | |名称==“”）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“我想知道你是谁！”；
}
if（document.contact.name.value.length您只是将与字段相关的所有条件称为if
，但实际上您需要将它们称为if..else
或if..else if..else
语句
如果您只提到If语句，那么它将执行一个字段的所有相关代码，最后它将显示您分配给innerHTML
的后一个值，该值在“Email字段”中始终为“Email太短”条件。
您只将与字段相关的所有条件称为if
，但实际上您需要将它们称为if..else
或if..else if..else
语句
如果您只提到If语句，那么它将执行一个字段的所有相关代码，最后它将显示您分配给innerHTML
的后一个值，该值在“Email字段”中始终为“Email太短”条件。
使其成为一个elseif
，而不是有两个独立的条件：
if(name == null || name == "") {
success = false;
  document.getElementById("name-error").innerHTML = "I want to know who you are!";
}
else if(document.contact.name.value.length <= 5) {
 success = false;
document.getElementById("name-error").innerHTML = "Full name, please!";  
}

if（name==null | | name==“”）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“我想知道你是谁！”；
}
else if（document.contact.name.value.length将其转换为elseif
，而不是具有两个独立的条件：
if(name == null || name == "") {
success = false;
  document.getElementById("name-error").innerHTML = "I want to know who you are!";
}
else if(document.contact.name.value.length <= 5) {
 success = false;
document.getElementById("name-error").innerHTML = "Full name, please!";  
}

if（name==null | | name==“”）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“我想知道你是谁！”；
}
else if（document.contact.name.value.length这是您的修复代码：
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Form validation</title>
<script>
function validation() {

    var name = document.getElementById("name").value.trim();
    var email = document.getElementById("email").value.trim();
    var subject = document.getElementById("subject").value.trim();
    var message = document.getElementById("message").value.trim();
    var at = "@";
    var dot = ".";
    var lat = email.indexOf(at);
    var lstr = email.length;
    var ldot = email.indexOf(dot);

    var success = true;

    if(name == null || (name.length)==0) {
        success = false;
        document.getElementById("name-error").innerHTML = "I want to know who you are!";
    }else{          
        document.getElementById("name-error").innerHTML = "";
    }

    if(name.length > 1 && document.contact.name.value.length < 5) {
        success = false;
        document.getElementById("name-error").innerHTML = "Full name, please!";  
    }

    if(email == null || email.length==0) {
        success = false;
        document.getElementById("email-error").innerHTML = "Give me your email!";
    }else{
        document.getElementById("email-error").innerHTML = "";
    }       

    if(email.length > 1 && document.contact.email.value.length <= 8){
        success = false;
        document.getElementById("email-error").innerHTML = "Email is too short!";     
    }

    if(email.length > 8 && email.indexOf(at) == -1 || email.indexOf(at) == 0 || email.indexOf(at) == lstr){
        success = false;
        document.getElementById("email-error").innerHTML = "That's not an email!";
    }   

    if(subject == null || subject.length==0) {
        success = false;
        document.getElementById("subject-error").innerHTML = "I need a subject!";
    }else{
        document.getElementById("subject-error").innerHTML = "";
    }

    if(subject.length > 0 && document.contact.subject.value.length <= 5){
        success = false;
        document.getElementById("subject-error").innerHTML = "A longer subject would be nice.";  
    }

    if(message == null || message.length==0) {
        success = false;
        document.getElementById("message-error").innerHTML = "Don't forget your message!";
    }else{
        document.getElementById("message-error").innerHTML = "";
    }

    if(message.length > 0 && document.contact.message.value.length <= 30){
        success = false;
        document.getElementById("message-error").innerHTML = "Your message is too concise!"; 
    }

    return success;

}
</script>
</head>
<body>
<form action="" method="post" name='contact'>
    <input type="text" name="name" id="name" value=''/>
    <span id="name-error"></span>
    <br />
    <input type="text" name="email" id="email" value=''/>
    <span id="email-error"></span>
    <br />
    <input type="text" name="subject" id="subject" value=''/>
    <span id="subject-error"></span>
    <br />
    <input type="text" name="message" id="message" value=''/>
    <span id="message-error"></span>
    <br />
    <input type="button" value="Send" onclick='return validation();'>
</form>

</body>
</html>


表单验证
函数验证（）{
var name=document.getElementById（“name”）.value.trim（）；
var email=document.getElementById（“email”）.value.trim（）；
var subject=document.getElementById（“subject”）.value.trim（）；
var message=document.getElementById（“message”）.value.trim（）；
var at=“@”；
var dot=“.”；
var lat=email.indexOf（at）；
var lstr=email.length；
var ldot=email.indexOf（dot）；
var成功=真；
if（name==null | |（name.length）==0）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“我想知道你是谁！”；
}否则{
document.getElementById（“名称错误”）.innerHTML=“”；
}
if（name.length>1&&document.contact.name.value.length<5）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“请输入全名！”；
}
如果（email==null | | email.length==0）{
成功=错误；
document.getElementById（“电子邮件错误”）.innerHTML=“给我你的电子邮件！”；
}否则{
document.getElementById（“电子邮件错误”）.innerHTML=“”；
}       
如果（email.length>1&&document.contact.email.value.length 8&&email.indexOf（at）=-1 | email.indexOf（at）==0 | email.indexOf（at）==lstr）{
成功=错误；
document.getElementById（“电子邮件错误”）.innerHTML=“那不是电子邮件！”；
}   
if（subject==null | | subject.length==0）{
成功=错误；
document.getElementById（“主题错误”）.innerHTML=“我需要一个主题！”；
}否则{
document.getElementById（“主题错误”）.innerHTML=“”；
}
如果（subject.length>0&&document.contact.subject.value.length 0&&document.contact.message.value.length，这是您的修复代码：
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Form validation</title>
<script>
function validation() {

    var name = document.getElementById("name").value.trim();
    var email = document.getElementById("email").value.trim();
    var subject = document.getElementById("subject").value.trim();
    var message = document.getElementById("message").value.trim();
    var at = "@";
    var dot = ".";
    var lat = email.indexOf(at);
    var lstr = email.length;
    var ldot = email.indexOf(dot);

    var success = true;

    if(name == null || (name.length)==0) {
        success = false;
        document.getElementById("name-error").innerHTML = "I want to know who you are!";
    }else{          
        document.getElementById("name-error").innerHTML = "";
    }

    if(name.length > 1 && document.contact.name.value.length < 5) {
        success = false;
        document.getElementById("name-error").innerHTML = "Full name, please!";  
    }

    if(email == null || email.length==0) {
        success = false;
        document.getElementById("email-error").innerHTML = "Give me your email!";
    }else{
        document.getElementById("email-error").innerHTML = "";
    }       

    if(email.length > 1 && document.contact.email.value.length <= 8){
        success = false;
        document.getElementById("email-error").innerHTML = "Email is too short!";     
    }

    if(email.length > 8 && email.indexOf(at) == -1 || email.indexOf(at) == 0 || email.indexOf(at) == lstr){
        success = false;
        document.getElementById("email-error").innerHTML = "That's not an email!";
    }   

    if(subject == null || subject.length==0) {
        success = false;
        document.getElementById("subject-error").innerHTML = "I need a subject!";
    }else{
        document.getElementById("subject-error").innerHTML = "";
    }

    if(subject.length > 0 && document.contact.subject.value.length <= 5){
        success = false;
        document.getElementById("subject-error").innerHTML = "A longer subject would be nice.";  
    }

    if(message == null || message.length==0) {
        success = false;
        document.getElementById("message-error").innerHTML = "Don't forget your message!";
    }else{
        document.getElementById("message-error").innerHTML = "";
    }

    if(message.length > 0 && document.contact.message.value.length <= 30){
        success = false;
        document.getElementById("message-error").innerHTML = "Your message is too concise!"; 
    }

    return success;

}
</script>
</head>
<body>
<form action="" method="post" name='contact'>
    <input type="text" name="name" id="name" value=''/>
    <span id="name-error"></span>
    <br />
    <input type="text" name="email" id="email" value=''/>
    <span id="email-error"></span>
    <br />
    <input type="text" name="subject" id="subject" value=''/>
    <span id="subject-error"></span>
    <br />
    <input type="text" name="message" id="message" value=''/>
    <span id="message-error"></span>
    <br />
    <input type="button" value="Send" onclick='return validation();'>
</form>

</body>
</html>


表单验证
函数验证（）{
var name=document.getElementById（“name”）.value.trim（）；
var email=document.getElementById（“email”）.value.trim（）；
var subject=document.getElementById（“subject”）.value.trim（）；
var message=document.getElementById（“message”）.value.trim（）；
var at=“@”；
var dot=“.”；
var lat=email.indexOf（at）；
var lstr=email.length；
var ldot=email.indexOf（dot）；
var成功=真；
if（name==null | |（name.length）==0）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“我想知道你是谁！”；
}否则{
document.getElementById（“名称错误”）.innerHTML=“”；
}
if（name.length>1&&document.contact.name.value.length<5）{
成功=错误；
document.getElementById（“名称错误”）.innerHTML=“请输入全名！”；
}
如果（email==null | | email.length==0）{
成功=错误；
document.getElementById（“电子邮件错误”）.innerHTML=“给我你的电子邮件！”；
}否则{
document.getElementById（“电子邮件错误”）.innerHTML=“”；
}       
如果（email.length>1&&document.contact.email.value.length 8&&email.indexOf（at）=-1 | email.indexOf（at）==0 | email.indexOf（at）==lstr）{
成功=错误；
document.getElementById（“电子邮件错误”）.innerHTML=“那不是电子邮件！”；
}   
if（subject==null | | subject.length==0）{
成功=错误；
document.getElementById（“主题错误”）.innerHTML=“我需要一个主题！”；
}否则{
document.getElementById（“主题错误”）.innerHTML=“”；
}
if（subject.length>0&&document.contact.subject.value.length 0&&document.contact.message.value.length使用else if
s。这样，只有一个错误将innerHTML
ed。而不是在每个块中设置successfalse
，而是首先将其保持为false。如果else，则使用else