Learn PHP for new users. I have a few questions about Arrays. I hope you can give me some advice.

Learn PHP for new users. I have a few questions about Arrays. I hope you can give me some advice.

". $ _ POST ['xh'] [$ I]."What does this sentence mean? Why should I add "[" xh "]"? Two "."What does it mean?
Why does $ XH get an array after submission? Isn't the array () function used to create an array?

Reply to discussion (solution)

Is a string connection operation.

Why should I use html arrays like name = 'xh [] '?
Reference
Http://php.net/manual/zh/faq.html.php#faq.html.arrays

In fact, this is the case when the browser posts the past data (located below the http header)

Xh [] = first value & xh [] = second value

Php will resolve
$ _ POST ['xh'] = array (
0 => 'first value ',
1 => 'second value'
)

Therefore, $ _ POST ['xh'] [0] will obtain the 'first value'

Normally (no form array is used)
Browser end


After the POST is sent to the server, php will parse it
$ _ POST ['xh'] = 0;

Here. it does not work. for example, the first floor is the operator that connects strings. "A". "B" = "AB"

Is a string connection operation.

Not very understandable... If it is a reference, isn't it necessary to add a. in front of the variable? Why should I add a. after the front and the back? if I remove the later one, an error is returned ..

    echo "";

Echo is followed by three strings (double quotation marks are red below)
The first one is :" The third is: "'>"

I am not used to concatenate strings in this way and use printf or sprintf functions similar to c.

printf("", $_POST['xh'][$i] );

    echo "";

Echo is followed by three strings (double quotation marks are red below)
The first one is :" The third is: "'>"

I am not used to concatenate strings in this way and use printf or sprintf functions similar to c.

printf("", $_POST['xh'][$i] );

Well, I have understood the code more recently ..
Thank you ~~