我正在为我的课程做一个食谱计算器。我已经到了可以正确验证所有内容并在表格中创建新行的阶段。可悲的是，在配方函数中的 if 语句中，isNaN 总是如此？不管我放什么？谁能帮我这个？
<!DOCTYPE html>
<html>
<head>
<title>Website Title</title>
<script type="text/javascript">
// Declare all variables
var ingredient = document.getElementById("ingredient").value;
var amount = document.getElementById("number").value;
var unit = document.getElementById("unit").value;
var ingredientcount = 0
// The save function
function save(){
var verified = true;
while(verified){
var name = prompt("What's the name of the recipe?")
var serves = prompt("How many people does it serve?")
if(serves === "" || name === "" || isNaN(serves)=== true)
{
alert("You have to enter a name, followed by the number of people it serves. Try again.")
verified = false;
}
else{
alert("sucess!");
// array(ingredient,amount,unit,name,serves)
return;
}
}
}
// The function to valiate the data and manage everything
function recipe(){
if(ingredient === ""|| amount === "" || unit === "Select Unit"){
alert("You must fill in all fields.")
}
else if(isNaN(amount)){
alert("You have to enter a number in the amount field")
}
else{
alert("hey!")
alert(recipe[1][2] + recipe[1][1])
var totalamount = amount + " "+ unit
insRow(ingredient, totalamount) // post(0,*123456*,"Fish")
ingredientcount ++;
alert(ingredientcount);
}
}
</script>
</head>
<body>
<h1>Recipe Name</h1>
<h2>Serves many people </h2>
<table border="1" id="table" >
<tr>
<td>
<input type="text" id="ingredient" placeholder="Enter an Ingredient">
</td>
<td>
<input type="text" id="number" placeholder="Enter an amount">
<select id="unit">
<option>Select Unit</option>
<option>Grams</option>
<option>Mililitres</option>
<option>Number</option>
</select>
</td>
<td>
<button type="button" onclick="recipe()">Add</button>
<button type="button" onclick="save()">Save</button>
</td>
</tr>
<th>Ingredient</th>
<th>Amount</th>
<th> </th>
</table>
</body>
</html>