Var_dump (bool )?) Related questions

Source: Internet
Author: User
Tags type null
Var_dump (bool )?) Var_dump (bool) & quot;); bool (false) var_dump (bool) 1); bool (true) var_dump (bool)-2 ); bool (true) var_dump (bool) & quot; f var_dump (bool )?) Problems
Var_dump (bool) ""); // bool (false)
Var_dump (bool) 1); // bool (true)
Var_dump (bool)-2); // bool (true)
Var_dump (bool) "foo"); // bool (true)
Var_dump (bool) 2.3e5); // bool (true)
Var_dump (bool) array (12); // bool (true)
Var_dump (bool) array (); // bool (false)
Var_dump (bool) "false"); // bool (true)

In the past, if it is not 0, it is TRUE, but var_dump (bool) array () is also false. how can I determine TRUE or false in PHP?

------ Solution --------------------
If the value is not 0, the value is TRUE.
------ Solution --------------------
In PHP, when other types of variables are converted to boolean, the following values are considered FALSE:

Boolean value: FALSE;
Integer value 0 (zero );
Floating point value: 0.0 (0 );
Null string (""), and string ("0 ");
Array that does not contain any elements;
Objects that do not include any member variables (applicable only to PHP 4.0 );
Special type NULL (including unset variables );
SimpleXML object generated from an XML document without any tags;

All other values are considered to be TRUE (including any resources ).

Note:-1 is considered TRUE like other non-zero values (both positive and negative values!

Var_dump (bool) ""); // bool (false)
Var_dump (bool) 1); // bool (true)
Var_dump (bool)-2); // bool (true)
Var_dump (bool) "foo"); // bool (true)
Var_dump (bool) 2.3e5); // bool (true)
Var_dump (bool) array (12); // bool (true)
Var_dump (bool) array (); // bool (false)
Var_dump (bool) "false"); // bool (true)
?>

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.