我如何使用node.js +猫鼬正确地比较moment.js中的日期

Question

I have two dates that I would like to compare , current date and future date

in my mongodb database (I'm using mongoose as its ORM)

var User = mongoose.Schema({
    future_month: String
});

This is futureMonth value

future_month = moment().add(1, 'M').format('DD-MM-YYYY');

and I tried to compare the current date and future date

exports.isTrue = function() {
    var currentDate = moment().format("DD-MM-YYYY");
    if (currentDate <= req.user.future_month) {
       console.log("Still Active");
    } else {
       console.log("You have to pay");
    }
}

I always get "You have to pay" even though

currentDate = 31-10-2015
req.user.future_month = 30/11/2015

It is supposed to run "Still Active" because currentDate is less than req.user.future_month value

and one more thing the typeof currentDate and future_month are both strings, that's why I put mongoose field as a string type. Just to let you guys know.

Answer 1

You are trying to compare strings. That won't work in most cases, especially with the format you're using. Instead, compare moment objects, and use the built-in functions rather than comparison operators.

// get the start of the current date, as a moment object
var today = moment().startOf('day');

// parse the input string to a moment object using the format that matches
var future = moment(req.user.future_month, "DD/MM/YYYY");

// use the isAfter function to compare
if (future.isAfter(today)) {
    ...

Note that I used isAfter function and flipped the sides of the comparison because you had today <= future , and moment only has isAfter and isBefore . If instead you had today < future , then I'd written it as today.isBefore(future) instead.

Also note that the startOf('day') will usually be midnight, but not always, due to time zones and DST. :)