Basic Javascript tutorials-if condition statements and basic javascript tutorials

Source: Internet
Author: User

Basic Javascript tutorials-if condition statements and basic javascript tutorials

If is one of the common syntaxes, the format is as follows:

If (coditon) statement1 (else statement2)

Coditon can be any expression, or even a Boolean value, because JavaScript will automatically convert it to a Boolean value.

If the condition execution result is true, statement1 is executed. If the condition is false, statment2 is executed. (If statement2 exists, else is not required)

Each condition statement can be a single line of code or a code block. The following is a simple example.

Copy codeThe Code is as follows:
Var iNumber = Number (prompt ("enter a Number between 5 and 100 "));
If (isNaN (iNumber ))
Document. write ("are you sure you entered the number. ");
Else if (iNumber> 100 | iNumber <5)
Document. write ("the value you entered is out of the range ");
Else
Document. write ("the value you entered is" + iNumber );

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.