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Javascript bool变量超出范围_Javascript - Fatal编程技术网

Javascript bool变量超出范围

Javascript bool变量超出范围,javascript,Javascript,我试图声明bool变量,然后在函数内部检查它,但我得到一个错误,即有一个意外的标识符指向daysCreated与false <script type="text/javascript"> var daysCreated = false; function createDays() { if daysCreated == false { //do something } daysCreated = true; } } var daysCreated

我试图声明bool变量,然后在函数内部检查它,但我得到一个错误,即有一个意外的标识符指向daysCreated与
false

<script type="text/javascript">

var daysCreated = false;

function createDays() {
 if daysCreated == false {
    //do something
    }
    daysCreated = true;
  }
}

var daysCreated=false;
函数createDays(){
如果daysCreated==false{
//做点什么
}
daysCreated=true;
}
}

在文档内部单击按钮时调用函数
createDays

您忘记了括号

function createDays() {
 if (daysCreated === false) {
    //do something
  }
  daysCreated = true;
}
此外,您还有一个错误的右大括号,最好检查是否严格相等(例如,
==


用一根门楣就能把这样的东西从大门里抓出来。举个例子。

这与范围无关

if
测试必须在括号之间:
if(条件)


这是无效的。您的if语句需要括号,如下所示:

function createDays() {
 if (daysCreated == false) {
    //do something
  }
  daysCreated = true;
}
你有打字错误

function createDays() {
   if (daysCreated === false) {
       //do something
   }
   daysCreated = true;
}

有一个错误的{

这是无效的语法。
if
中的条件需要用括号括起来。顺便说一句,if(!daysCreated)…可能重复。我可能会将参数传递给函数,而不是使用全局的
daysCreated
-并返回该“内部”值,可能会使代码更加模块化。
function createDays() {
   if (daysCreated === false) {
       //do something
   }
   daysCreated = true;
}