添加 if 语句后，我的“提示”不会加载到网页上答案

【问题标题】：My "prompt" won't load on the web page after i added the if statements添加 if 语句后，我的“提示”不会加载到网页上
【发布时间】：2018-08-07 13:05:30
【问题描述】：

所以我单独测试了提示，它工作正常，但在我添加文本之后似乎没有加载。请帮忙。

var myage = parseInt(prompt("enter age ", 30), 10);

if (myage >= 0 && myage <= 10) {
  document.write("myage is between o and 10 <br/>");
}

if (!(myage >= 0 && myage <= 10)) {
  document.write(" myage is not between 0 and 10 <br/>");
}

if (myage >= 80 || myage <= 10) {
  document.write("myage is equal to or above 80 or 10 or less");
}

if ((myage >= 30 && myage <= 39) || (myage >= 80 && <= 89)) {
  document.write("myage is between 30 and 39 or myage is " + "between 80 and 89");

}

【问题讨论】：

您的代码在最后一次if 测试中有语法错误。这就是为什么您应该始终打开开发者控制台。
干杯我知道这是一个微不足道的错误，但感谢您的建议

标签： javascript if-statement prompt

【解决方案1】：

在最后的if 语句中，您忘记将我的myage 添加到值检查中；您刚刚编写了 <= 运算符，没有要比较的变量值。

您应该在调试时打开控制台。控制台显示“Uncaught SyntaxError: Unexpected token

改变

if ((myage >= 30 && myage <= 39) || (myage >= 80 && <= 89/*missing variable to check the value of*/)) {
  document.write("myage is between 30 and 39 or myage is " + "between 80 and 89");

}

到

if( (myage>=30 && myage<=39)||(myage>=80&&myage<=89)) {
      document.write ("myage is between 30 and 39 or myage is " + "between 80 and 89");
}

var myage = parseInt ( prompt("enter age ", 30) , 10);

if (myage >= 0 && myage <= 10) {
  document.write("myage is between o and 10 <br/>");
}

if (!(myage >= 0 && myage <= 10 )){
  document.write(" myage is not between 0 and 10 <br/>");
}

if (myage>=80||myage<=10) {
  document.write("myage is equal to or above 80 or 10 or less");
}

if( (myage>=30 && myage<=39)||(myage>=80&&myage<=89)) {
  document.write ("myage is between 30 and 39 or myage is " + "between 80 and 89");
}

【讨论】：

是的，就是为帮助而欢呼。我终于可以继续前进了
@TheoBrown 没问题。

【解决方案2】：

你错过了最后一个条件myage。

var myage = parseInt(prompt("enter age ", 30), 10);

if (myage >= 0 && myage <= 10) {
  document.write("myage is between o and 10 <br/>");
}

if (!(myage >= 0 && myage <= 10)) {
  document.write(" myage is not between 0 and 10 <br/>");
}

if (myage >= 80 || myage <= 10) {
  document.write("myage is equal to or above 80 or 10 or less");
}

if ((myage >= 30 && myage <= 39) || (myage >= 80 && myage <= 89)) {
  document.write("myage is between 30 and 39 or myage is " + "between 80 and 89");

}

【讨论】：