How to implement the online clock function of web pages in javascript

Method: 1. Use the Date method with getHours, getMinutes and getSeconds methods to obtain the hours, minutes and seconds of the current time; 2. Use the "setInterval (function name to obtain time, 1000)" statement to set each Just refresh the obtained time once every second.

The operating environment of this tutorial: Windows 10 system, JavaScript version 1.8.5, Dell G3 computer.

How does javascript implement the online clock function of a webpage?

Javascript is a scripting language based on Object and Event Driven , which runs on the client side, thus reducing the burden on the server side. A complete JavaScript is composed of core syntax, browser object model and document object model. Now, let me share with you how to implement a small function on the page, the clock is displayed in real time.

Create date object: Date object contains two information: date and time. There are two basic syntaxes for creating date object:

Method 1: var date instance = new Date (parameter);

Method 2: var date instance=new Date();

Get the date, time, etc. through the get method of the Date object. In order to display on the page, it can be set using the innerHTML attribute in the DOM.

#Use the if statement to determine whether the current hour is greater than 12 to determine morning and afternoon.

How to display it in real time? There are two timing functions provided in javascript: setTimeout() and setInterval().

• setTimeout(): Used to call a function or calculated expression after a specified number of milliseconds.

• setInterval(): You can call a function or calculate an expression according to the specified period (in milliseconds).

It is obviously chosen to use the setInterval() method to achieve this, and the page displays the time in real time.

Through the above steps, the code design for real-time time display is completed. The complete code is as follows:

Finally, the operation is OK and the operation effect is as the picture shows. Note that the time changes in real time at this time, that is, it changes once every second.

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