如何检查日期是否大于另一个日期？

Question

I have 2 dates. Both are in yyyy-mm-dd format. I applied a simple check that if

if ('2017-01-15' > '2016-12-15') { 
    return true; 
} else { 
    return false; 
}

But it is giving me a syntax error. What should I do?

Answer 1

Given the format of the date string and your code structure, what you have should be working. If you're getting an error, check that it's coming from the section of code you've shown in your question.

That being said, you can improve the code by changing the strings to Date objects before comparing them. You can also shorten the code by just returning the result of the comparison. Try this:

 function dateComparison() { return new Date('2017-01-15') > new Date('2016-12-15'); } console.log(dateComparison()); 

Answer 2

As per the MDN

The return statement ends function execution and specifies a value to be returned to the function caller.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/return

So you must be getting this error if you are not using the if condition within a function.

Answer 3

Operators like ==, !=, ===, and !== require you to use date.getTime() like this:

var x = new Date('2017-01-15');
var y = new Date('2016-12-15');  
var same = x.getTime() === y.getTime();
var notSame = x.getTime() !== y.getTime();

Answer 4

您可以使用moment.js库来帮助您实现：

return moment('2017-01-15').format('YYYY-MM-DD') > moment('2016-12-15').format('YYYY-MM-DD');

Answer 5

You could convert them to Date objects and then compare.

var dateStrA = "2017-01-15 00:00:00";
var dateStrB = "2016-12-15 00:00:00";

if (new Date(dateStrA) > new Date(dateStrB))
{
     ...
}
else
{
    ...
}

Comparing using equals, such as === will not work on Date objects. You can also use Date.compare()

Answer 6

Try this...worked for me.  

  var startDate = "2019-03-23"; var endDate = "2019-03-24"; if(Date.parse(endDate) >= Date.parse(startDate)) { console.log('endDate is greater'); } else { console.log('startDate is greater'); } 

Answer 7

你可以试试这个

    if(d1.getTime()>d2.getTime())