A bit of confusion about arrays how to solve

Source: Internet
Author: User
A bit of confusion about arrays
PHP Code
  $arr = Array (); $num = ' Hello World '; if (Isset ($num)) {    $arr = $num;    Var_dump ($arr);} else {    $arr [] = Array (All-in-all);    Var_dump ($arr);}

After running, the browser displays the string type

But I have set arr to be an array, do not understand the intrinsic reason, or $arr = $num; This sentence has been re-declared a variable arr???

This is the weak type ...

$STR = "123";
echo$str[0];//, it's okay. Output 1
The type of the variable can be automatically transformed with the context, which is known as a weak type

You have $arr = $num; So $arr becomes a string.
PHP types change at any time, forcing type conversions, like this: Var_dump ((array) $arr);
  • 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.