Question

我的家庭作业是像聚会一样进行活动，然后给出四个年龄段的价格。用户应该输入他们的年龄，并且它将告诉他们所支付的价格。我还想告诉用户是否输入了错误的数字，例如0或1000或一个单词，但是由于我从未教过怎么做，所以我还没有弄清楚该怎么做。

<form id= "age">

    <p><input type= "text" value= "Enter age" id= "text1"></p>

 <p><button class="w3-button w3-black" type="button" onclick= "message1" id= "button">Amount Due</button></p>

    </form>

  </div>

</div>

</div>

</div>

<script>

var age

function message1 () {

if (age >= 0 && age => 12) {

window.alert("You are not eligible to go to this event")

} if ( age => 13 && age => 18) {

window.alert("Your amount due is $5.00")

} if (age => 19 && age => 24) {

window.alert("Your amount due is $7.00")

} if (age => 25 && age => 54) {

window.alert("Your amount due is $9.00")

} if (age => 55 && age => 99) {

window.alert("Your amount due is $11.00")

}

}
    </script>

Answer 1

获得灵感的快速答案：

const formAge = document.getElementById('form-Age')

formAge.onsubmit = function(evt)
{
  evt.preventDefault()
  alert( message1(formAge.age.valueAsNumber))
}

function message1(age)
{
  if (age < 13)  return "You are not eligible to go to this event"
  if (age < 19)  return "Your amount due is $5.00"
  if (age < 25)  return "Your amount due is $7.00"
  if (age < 55)  return "Your amount due is $9.00"
  return "Your amount due is $11.00"
}

<form id="form-Age">
  <p>Enter age : <input type="number" name="age" min="0" max="99" value="0"></p>
  <p><button class="w3-button w3-black" type="submit">Amount Due</button></p>
</form>

Answer 2

函数名称需要使用方括号。

<form id= "age">

    <p><input type= "number" min="1" max="150" value= "Enter age" id= "text1"></p>

 <p><button class="w3-button w3-black" type="button" onclick= "message1()" id= "button">Amount Due</button></p>

    </form>

只需使用基于id的jQuery选择器获取值。使用<=小于等于。并使用Alert而不是window.alert。在每个语句后使用分号。

如果您想开始进行Web开发，请点击here！

<script>
function message1 () {

var age = $("#text1").val();

if (age >= 0 && age <= 12) {

alert("You are not eligible to go to this event");

} if ( age >= 13 && age <= 18) {

alert("Your amount due is $5.00");

} if (age >= 19 && age <= 24) {

alert("Your amount due is $7.00");

} if (age >= 25 && age <= 54) {

alert("Your amount due is $9.00");

} if (age >= 55 && age <= 99) {

alert("Your amount due is $11.00");

}

}
</script>

事件没有给我结果

2 个答案: