Question

我正在获得单个表单的双重警报提示：第一次弹出警报，然后当我单击“确定”时，同一个警告再次弹出。我认为我的代码应该在遇到“else window.alert（sameWarning）时执行一次警报，并在达到”return false（）“时停止;但似乎返回false（）导致警报两次。也许是因为我有在一个页面上有两个表单;但是，它们有两个单独的函数名称（“signinForm（）”和“saveSignUp（）”）并调用两个单独的表单（表单[0]和表单[1]）？我认为我的代码是正确的，但我现在无法弄明白。任何帮助都会受到赞赏。提前致谢！

<script type="text/javascript">
//FIRST FUNCTION FOR FORMS[0]
function signinForm(){

        // var sameWarning = "The required fields were not submitted for the following error(s).  \n \n";
        var warningLogin = "The following field(s) require an entry: \n \n";
        var sameWarning = warningLogin;

        var userName = document.forms[0].userName.value;
        var pswd = document.forms[0].pswd.value;

        if(userName == ""){ 
        sameWarning += " - First Name \n";
        }

        if(pswd == ""){ 
        sameWarning += " - Password \n";
        }

        if (warningLogin == sameWarning){ 
            return true; 
            }

        else  { 
            window.alert(sameWarning);  
        }
    return false;   
   }

//SECOND FUNCTION CALL FOR FORMS[1] 
function saveSignUp(){

        // var warning = "The required fields were not submitted for the following error(s).  \n \n";
        var warning = "The following field(s) require an entry: \n \n";
        var same = warning;

        var firstName = document.forms[1].firstName.value;
        var lastName = document.forms[1].lastName.value;
        var email = document.forms[1].email.value;
        var phone = document.forms[1].phoneNumber.value;

        if(firstName == ""){ 
        //firstName.style.backgroundColor="red";
        warning += " - First Name \n";
        }

        if(lastName == ""){ 
        warning += " - Last Name \n";
        }

        if(email == ""){ 
        warning += " - Email \n";
        }

        if(phone == ""){ 
        warning += " - Work Phone \n";
        }

        if(phone < 5 ){
            warning += " - Must be a numberssss \n";
            }

        if (warning == same){
            return true; 
        } 

        else  { 
            alert(warning);         
        }
    return false;
   }

</script>

HTML

<h1>Login</h1>
<form method="post" onsubmit="return signinForm();" action="" >
    <input type="text" placeholder="Username/Email" name="userName">
    <input type="password" placeholder="Password" name="pswd" id="pswd">
    <input type="submit" onclick="signinForm();" value="Sign In">
</form>
<h1>Sign Up!</h1>
    <form method="post" onsubmit="return saveSignUp()" action="" >
    <input type="text" placeholder="First Name" name="firstName">
    <input type="text" placeholder="Last Name" name="lastName">
    <input type="text" placeholder="Email" name="email">
    <input type="text" placeholder="Phone Number" name="phoneNumber">
    <input type="submit" onclick="saveSignUp();" class="button wide" value="Request an Account">

Answer 1

这是因为你两次致电signinForm();。

删除其中一个侦听器

onclick="signinForm();"

onsubmit="return signinForm()"

当您点击提交按钮时，请致电signinForm();。因为它是submit按钮，它会触发onsubmit事件，并调用return signinForm()

Answer 2

当你点击提交时，首先它会触发click事件（调用你的函数），然后它会触发一个提交事件（再次调用你的函数）。只需删除提交按钮的onclick。

双重警报Windows

2 个答案: