javascript 参考错误：日期未定义
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/15123973/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
ReferenceError: date is not defined
提问by user2084813
I have some code here where I get a value from a form represented by "adate". Then I split the string the user enters at the hyphen and separate each value into year, month and day as you can see. I use those values to define a date object. My console correctly displays the date, but I keep getting this error also showing up. Am I defining the date incorrectly? I'm not sure what the issue is.
我在这里有一些代码，我从“日期”表示的表单中获取值。然后我拆分用户在连字符处输入的字符串，并将每个值分成年、月和日，如您所见。我使用这些值来定义日期对象。我的控制台正确显示日期，但我也不断收到此错误。我是否错误地定义了日期？我不确定是什么问题。
function getFormData() {
var task = document.getElementById("task").value;
if (checkInputText(task, "Please enter a task")) return;
var who = document.getElementById("who").value;
if (checkInputText(who, "Please enter a person to do the task")) return;
var adate = document.getElementById("dueDate").value;
var reString = new RegExp("[0-9]{4}\-\[0-9]{2}\-\[0-9]{2}");
if ( adate.match(reString)) {
processDate(adate) }
else {
alert("you did not enter the date in the correct format")
};
var id = (new Date()).getTime();
var todoItem = new Todo(id, task, who, date);
todos.push(todoItem);
addTodoToPage(todoItem);
saveTodoItem(todoItem);
hideSearchResults();
}
function processDate(adate) {
var splitArray = new Array();
splitArray = adate.split("-");
var year = splitArray[0];
var month = splitArray[1] - 1;
var day = splitArray[2];
var date = new Date(year, month, day);
console.log(date);
}
回答by bfavaretto
Make your function return the date, because the datevariable in there is not visible to the outside:
让你的函数返回日期，因为date那里的变量对外不可见：
function processDate(adate) {
var splitArray = new Array();
splitArray = adate.split("-");
var year = splitArray[0];
var month = splitArray[1] - 1;
var day = splitArray[2];
return new Date(year, month, day);
}
Then assign to a new variable when you call it:
然后在调用它时分配给一个新变量：
var date = processDate(adate);
The error actually originated in the following line, because you were referencing a non-existing datevariable:
该错误实际上起源于以下行，因为您引用了一个不存在的date变量：
var todoItem = new Todo(id, task, who, date);
回答by RobG
Just a comment.
只是一个评论。
The RegExp constructor is usually only required where the expression is dynamically generated. Where you have a fixed expression, it's simpler to use a literal (as you don't have to quote certain characters). Also, to test the format, a more appropriate method is testrather than match.
RegExp 构造函数通常只在动态生成表达式时才需要。如果您有固定表达式，则使用文字会更简单（因为您不必引用某些字符）。此外，要测试格式，更合适的方法是test而不是match.
If the date format is: yyyy-mm-dd, consider:
如果日期格式为：yyyy-mm-dd，请考虑：
var reString = /^\d{4}-\d\d-\d\d$/; // trim leading and trailing white space?
if (reString.test(adate)) {
processDate(adate);
}
The date string validation should be in the processDatefunction, which might throw different errors depending on whether the format is incorrect or the date is invalid (e.g. 2013-02-29, which will return a date of 2013-03-01 in your current code).
日期字符串验证应该在processDate函数中，这可能会抛出不同的错误，具体取决于格式是否不正确或日期是否无效（例如 2013-02-29，它将在您当前的代码中返回 2013-03-01 的日期）。
