Question

我是JavaScript的新手并想要自己学习我有一个问题，我的警告框没有出现在Verify（）方法的第二种方法是我做错了什么或别的什么！请帮助我提前谢谢！我的代码：

<html>
    <head>

        <script>
            function Verify(){
                if(!isValidName()){
                    return false;   
                }

                 if(!isValidID()){
                    return false;
                 }
            }

            function isValidName(){
                var fnam=document.getElementById('fname').value;
                var lnam=document.getElementById('lname').value;
                var fcn=fnam.charAt(0);
                var lcn=lnam.charAt(0);

                    if(fnam==""||fnam=="First Name"){
                        alert("Please Enter First Name!");
                        return false;
                    }
                    else if(lnam==""||lnam=="Last Name"){
                        alert("Please Enter Last Name!");
                        return false;
                    }
                    else if(fcn!=fcn.toUpperCase()){
                        alert("Please Use Uppercase for the First Letter in the First Name!");
                        return false;
                    }
                    else if(lcn!=lcn.toUpperCase()){
                        alert("Please Use Uppercase for the First Letter in the Last Name!");
                        return false
                    }
                    else{
                        var fc=0;
                        for(i=0; i<fnam.length; i++){
                            fc+=1;
                            if(fnam.charAt(i)>=0||fnam.charAt(i)<=9){
                                alert("Your First Name Contains an Integer! at index="+fc);
                                return false;
                                break;
                            }
                        }
                        var lc=0;
                        for(j=0; j<lnam.length; j++){
                            lc+=1;
                            if(lnam.charAt(j)>=0||lnam.charAt(j)<=9){
                                alert("Your Last Name Contains an Integer! at index="+lc);
                                return false;
                                break;
                            }
                        }
                    }
            }

            function isValidID(){

                var g=document.getElementById('aaa').value;
                if(g=="abc"){
                    alert("SOMETHING WRONG!");
                    return false;
                }
            }

            function clearLastName(){
                document.getElementById('lname').value="";  
            }

            function clearFirstName(){
                document.getElementById('fname').value="";  
            }
        </script>
            <title>
                This is NIC Form Example 
            </title>
    </head>

    <body>
        <h1>
            This is NIC Form Example!
        </h1>
            <form name="nicform" onsubmit="return Verify()">
                <table border="1">
                    <tr>
                        <td>
                            First Name:
                        </td>
                            <td>
                                <input type="text" id="fname" value="First Name" onClick="clearFirstName()">
                            </td>
                    </tr>
                        <tr>
                            <td>
                                Last Name:
                            </td>
                                <td>
                                    <input type="text" id="lname" value="Last Name" onClick="clearLastName()">
                                </td>
                        </tr>
                            <tr>
                                <td>
                                    Gender:
                                </td>
                                    <td rowspan="2">
                                        Male:   <input type="radio" id="male" name="rad">
                                            <br/>
                                        Female: <input type="radio" id="female" name="rad">
                                    </td>
                            </tr>
                                <tr>
                                </tr>
                            <tr>
                            <td>
                            <input type="text" id="aaa" value="abc" >
                            </td>
                                <td align="center" colspan="2">
                                    <button type="submit">GO</button>
                                </td>
                            </tr>
                </table>
            </form>
    </body>
</html>

问题是，如果带有id＆＃39; aaa＆＃39;的字段的值保持不变，即如果提交表格，其价值是＆＃34; abc＆＃34;它没有显示警报框！

Answer 1

我认为永远不会调用第二种方法，因为如果每件事都是正确的，你会错过两个函数中的“return true”。所以如果你补充说它会解决你的问题。

如果函数1执行正确，则必须要求返回true。如下所示

    function Verify() {
                if (!isValidName()) {
                    return false;
                }

                if (!isValidID()) {
                    return false;
                }
            }

            function isValidName() {
                var fnam = document.getElementById('fname').value;
                var lnam = document.getElementById('lname').value;
                var fcn = fnam.charAt(0);
                var lcn = lnam.charAt(0);

                if (fnam == "" || fnam == "First Name") {
                    alert("Please Enter First Name!");
                    return false;
                }
                else if (lnam == "" || lnam == "Last Name") {
                    alert("Please Enter Last Name!");
                    return false;
                }
                else if (fcn != fcn.toUpperCase()) {
                    alert("Please Use Uppercase for the First Letter in the First Name!");
                    return false;
                }
                else if (lcn != lcn.toUpperCase()) {
                    alert("Please Use Uppercase for the First Letter in the Last Name!");
                    return false
                }
                else {
                    var fc = 0;
                    for (i = 0; i < fnam.length; i++) {
                        fc += 1;
                        if (fnam.charAt(i) >= 0 || fnam.charAt(i) <= 9) {
                            alert("Your First Name Contains an Integer! at index=" + fc);
                            return false;
                            break;
                        }
                    }
                    var lc = 0;
                    for (j = 0; j < lnam.length; j++) {
                        lc += 1;
                        if (lnam.charAt(j) >= 0 || lnam.charAt(j) <= 9) {
                            alert("Your Last Name Contains an Integer! at index=" + lc);
                            return false;
                            break;
                        }
                    }
                }
                return true;
            }

            function isValidID() {

                var g = document.getElementById('aaa').value;
                if (g == "abc") {
                    alert("SOMETHING WRONG!");
                    return false;
                }
                return true;
            }

            function clearLastName() {
                document.getElementById('lname').value = "";
            }

            function clearFirstName() {
                document.getElementById('fname').value = "";
            }

Answer 2

如果表单有效，则函数Verify()应返回true。

function Verify(){
            if(!isValidName()){
                return false;   
            }

             if(!isValidID()){
                return false;
             }
            return true;
        }

无法正确提交表格

2 个答案: