我有一个关于创建可以输入“成绩”的表格的问题，该表格还会检查这些成绩是否介于 0 到 25 或 0 到 100 之间(输入验证)。我的代码必须在 javascript 中，但我不知道从哪里或如何开始。换句话说，我需要使用这段代码并添加一个“表单”并检查有效输入。这是我目前所拥有的:
<!doctype html>
<html>
<script>
var a1=parseFloat(prompt("Enter the grade for assignment 1: "));
var a2=parseFloat(prompt("Enter the grade for assignment 2: "));
var a3=parseFloat(prompt("Enter the grade for assignment 3: "));
var a4=parseFloat(prompt("Enter the grade for assignment 4: "));
var mid=parseFloat(prompt("Enter the grade for the mid exam: "));
var fe=parseFloat(prompt("Enter the grade for the final exam: "));
var fp=parseFloat(prompt("Enter the grade for the final project: "));
var sum;
var grade;
var error;
sum=((a1+a2+a3+a4)/4)*(4*0.25)+(mid*0.25)+(fe*0.25)+(fp*0.25);
/* if (a1 < 0 && a1 > 25) {
error = window.prompt( "Assignments are only out of 25 points, please re-enter the integer grade:")
} */
if (sum >= 94.0) {
grade = "A";
} else if (sum <= 94.0 && sum >= 90.0) {
grade = "A-";
} else if (sum <= 90.0 && sum >= 87.0) {
grade = "B+";
} else if (sum <= 86.9 && sum >= 84.0) {
grade = "B";
} else if (sum <= 83.9 && sum >= 80.0) {
grade = "B-";
} else if (sum <= 79.9 && sum >= 77.0) {
grade = "C+";
} else if (sum <= 76.9 && sum >= 74.0) {
grade = "C";
} else if (sum <= 73.9 && sum >= 70.0) {
grade = "C-";
} else if (sum <= 69.9 && sum >= 67.0) {
grade = "D+";
} else if (sum <= 66.9 && sum >= 64.0) {
grade = "D";
} else if (sum <= 63.9 && sum >= 60.0) {
grade = "D-";
} else if (sum <= 60.0) {
grade = "F";
}
document.writeln("The final percent grade is "+sum+"%. Your grade letter is: "+grade+".");
</script>
</html>最佳答案
从 textboxes 中获取值并给出 button获取结果并在输出 div 中显示结果。
这是我的做法。
在 javascript 中，使用 document.getElementById("<ID>").value 从文本框中获取值并将其存储在一个变量中。对所有输入框执行相同的步骤。并处理从文本框获得的值并在 button 时显示它被点击。
这是一个简单的代码片段，它使用字段执行相同的操作。
function myFunction()
{
var a1 = parseFloat(document.getElementById("a1").value);
var a2 = parseFloat(document.getElementById("a2").value);
var a3 = parseFloat(document.getElementById("a3").value);
var a4 = parseFloat(document.getElementById("a4").value);
var mid = parseFloat(document.getElementById("mid").value);
var fe = parseFloat(document.getElementById("fe").value);
var fp = parseFloat(document.getElementById("fp").value);
var sum=((a1+a2+a3+a4)/4)*(4*0.25)+(mid*0.25)+(fe*0.25)+(fp*0.25);
var grade;
if (sum >= 94.0) {
grade = "A";
} else if (sum <= 94.0 && sum >= 90.0) {
grade = "A-";
} else if (sum <= 90.0 && sum >= 87.0) {
grade = "B+";
} else if (sum <= 86.9 && sum >= 84.0) {
grade = "B";
} else if (sum <= 83.9 && sum >= 80.0) {
grade = "B-";
} else if (sum <= 79.9 && sum >= 77.0) {
grade = "C+";
} else if (sum <= 76.9 && sum >= 74.0) {
grade = "C";
} else if (sum <= 73.9 && sum >= 70.0) {
grade = "C-";
} else if (sum <= 69.9 && sum >= 67.0) {
grade = "D+";
} else if (sum <= 66.9 && sum >= 64.0) {
grade = "D";
} else if (sum <= 63.9 && sum >= 60.0) {
grade = "D-";
} else if (sum <= 60.0) {
grade = "F";
}
document.getElementById("result").innerHTML = ("The final percent grade is "+sum+"%. Your grade letter is: "+grade+".");
}<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width">
<title>JS Bin</title>
</head>
<body>
a1: <input type="text" id="a1"><br><br>
a2: <input type="text" id="a2"><br><br>
a3: <input type="text" id="a3"><br><br>
a4: <input type="text" id="a4"><br><br>
mid: <input type="text" id="mid"><br><br>
finalexam: <input type="text" id="fe"><br><br>
finalproject: <input type="text" id="fp"><br><br>
<button onclick="myFunction()">Get Results</button><br><br>
<span id="result"></span>
</body>
</html>谢谢。
关于javascript - 使用 javascript 创建输入表单，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52639269/