我正在为问题的答案创建一个动态文本字段，用户可以从答案字段显示中选择该字段。当用户输入答案并提交表单时，php代码将用户的答案存储在名为$ans1的php变量中。提交后重新加载表单时，不会显示答案。我想在我动态创建的字段注释中显示这个答案。代码如下：
<?php
$ques1Err = $ans1Err = '' ;//variable to display error like field required
$ques1 = $ans1 = '' ;// variable to store value what user enter or select
$qans1 = 0;
if ($_SERVER["REQUEST_METHOD"] == "POST"){
if(empty($_POST['q1'])){
$ques1Err = 'Security Question Required' ;
}
else{
$ques1 = $_POST['q1'];
$qans1 = 1;
}
if(empty($_POST['ans1'])){
$ans1Err = 'Answer Required' ;
}
else{
$ans1 = check_input($_POST['ans1']);
if(!preg_match("/^[a-zA-Z ]*$/",$ans1)){
$ans1Err = "Only letters and white space allowed";
}
}
}
?>
<html>
<head>
<script>
// dynamically add input field for the user to enter the answer of question
function add_txt_field(){
var inpdiv = document.createElement("DIV");
inpdiv.setAttribute("class","input-txt");
var input = document.getElementById("answers1_txt-input");
input.appendChild(inpdiv);
var inp = document.createElement("INPUT");
inp.setAttribute("type","text");
inp.setAttribute("id","answers1");
inp.setAttribute("class","txt-box");
inp.setAttribute("name","answers1");
inp.setAttribute("value","");
inpdiv.appendChild(inp);
}
</script>
</head>
<body>
<form action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']);?>" method="post">
Security Question<select class="txt-box" onchange="add_txt_field()" id="q1" name="q1">
<option value="<?php echo $ques1 ?>"><?php echo $ques1 ?></option>
<option value="What was your childhood nickname?">What was your childhood nickname?</option>
<option value="What is your grandmother's first name?">What is your grandmother's first name?</option>
<option value="What school did you attend for sixth grade?">What school did you attend for sixth grade?</option>
</select><span class="error"> <?php echo $ques1Err;?></span></div>
<div id="answers1_txt-input"></div>
<?php
if($qans1 == 1){
echo '<script type="text/javascript"> add_txt_field() </script>';
***// here's the problem***
echo '<script> oFormObject.elements["answers1"].value = "$ans1" </script>' ;
}
?>
<button id="create" name="create" type="submit">Create</button>
</form>
</body
</html>
您的javascript:出现问题
echo '<script> oFormObject.elements["answers1"].value = "$ans1" </script>' ;
将其更改为此
echo '<script> document.getElementById("answers1").value = "'.$ans1.'"; </script>' ;
但是您也可以在表单中从php中执行一些操作，例如：
<?php
if (isset($ans1)) {
echo '<input type="text" name="answers1" id="answers1" value="'.$ans1.'"/>';
}
?>
而不是使用javascript