JavaScript uses two representations of „empty“ values. When „empty“ we mean that they don’t have an exact value assigned. These two values are null and undefined. Both values, null and undefined, are valuable in JavaScript. Except when you are not checking for them. In such cases, you’re running …

MongoDB requires each document to contain an _id field. If the _id field is not present when inserting a document, MongoDB generates an ObjectId for you. ObjectIds have a length of 12 bytes: 4-byte timestamp, 5-byte random value, and 3-byte incrementing counter. An ObjectId can be formatted as a hex …

MongoDB requires each document to contain an _id field. If the _id field is not present when inserting a document, MongoDB generates an ObjectId for you. You can use ObjectIds as the primary key in your application. When requesting information from the browser you may send an ObjectId as an …

Sometimes it’s helpful to translate dates into labels in your web application. For example, the human brain perceives the label „yesterday“ easier than translating the string of yesterday’s date to „yesterday“. This tutorial shows you how to calculate yesterday’s date in JavaScript. {{outline}} How Do You Get …

Working with dates in an application typically involves some kind of „shortcuts“. Like, such as adding a given number of days to a date. Adding days to a date could mean postponing a to-do item. This tutorial shows you how to add days to a date in JavaScript. {{outline}} Add …

The UNIX time describes a point in time using an integer value. This integer is the number of seconds since the UNIX epoch. The UNIX epoch is 01 January 1970 at 00:00:00 UTC. This tutorial shows you how to convert a UNIX timestamp to a JavaScript date instance. …

The UNIX time is a way to describe a point in time. You’re describing the time using an integer value. This value is the number of seconds since the UNIX epoch which is the UTC time of 01 January 1970 at 00:00:00. This tutorial shows you how …

The JavaScript engine comes with a global Date class. Interacting with dates is an essential part of programming. JavaScript’s Date comes with two methods to retrieve the current year: Date#getYear and Date#getFullYear. This tutorial shows you what to look out for when using one or another and …