Destruction of php-variables

Source: Internet
Author: User

Destruction of variables
Example
$a = 99;//unset($a);  //注释屏蔽中 所以不会使用if(isset($a)){    echo ‘a存在‘;}else{    echo ‘a不存在‘;}输出结果是:a存在,$a = 99;//unset($a);  //注释屏蔽中 所以不会使用if(isset($a)){    echo ‘a存在‘;}else{    echo ‘a不存在‘;}输出结果是:a不存在,已经使用unset将他删除了
a feature of unset ()Example:
$a = 99;$b = &$a;$b = 20;var_dump($a,$b);  // 20  20  一个改变 另一个都变echo "
Destruction of variables
Example
$a = 99;//unset($a);  //注释屏蔽中 所以不会使用if(isset($a)){    echo ‘a存在‘;}else{    echo ‘a不存在‘;}输出结果是:a存在,$a = 99;//unset($a);  //注释屏蔽中 所以不会使用if(isset($a)){    echo ‘a存在‘;}else{    echo ‘a不存在‘;}输出结果是:a不存在,已经使用unset将他删除了
a feature of unset ()Example:
$a = 99;$b = &$a;$b = 20;var_dump($a,$b);  // 20  20  一个改变 另一个都变echo "      当然, 如果C君也走了。 那么这个电视【代表值】,也就不需要存在了。 就没有人在看电视了。

Destruction of php-variables

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.