Bad Wolf's PHP Learning Tutorial Day 3 Page 1/2_PHP Tutorial

Today I’ve taken it to the next level... First write one: (adding numbers)

Copy the code The code is as follows:

$a = "10"; //"Connect" the right side to the left side
$a += "2"; //"Add" the right side to the left side
echo $a."
n"; //The result here is 12, which probably means that $a is equal to 10, and then add 2 to the left (which is $a), so it is 12.
?>

I think PHP writing pays great attention to the concept of rows. No matter what $a represents, it probably means right to left. "Connect to" or "Add to" or "Reduction to" etc.,! is not just the addition of numbers. There are other ways.
Write another: (right connection to left content)

Copy code The code is as follows:

$b = "Bad Wolf";
$b .= "Good guy!";
$b .= "Good guy!";
echo $b."Haha!n"; //Display the final content!
?>

Why are the results displayed like this? If you listen carefully every time, you will say in the previous paragraph: The running method of the program is from top to bottom, from right to left.


Write another one: (for division)

Copy code The code is as follows:

$a = "65896255618562314793123219"; //Complex calculation here, it turns out that php handles it here easily!
$a /= "465342233234234"; //Multiply these two numbers!
echo $a."←This is the result! 65896255618562314793123219 Except for 465342233234234, wow ordinary people are not as fast as me! Haha@! N "
? & Gt;

Get results 141608156132, the speed is really fast, haha ​​.... ..

Continue to the next big step:
1. Bit operation (this is rarely used)
& stands for and (and)
| stands for or (or)
^ represents mutual exclusion (Xor)
>> Shift right
~ Take the auxiliary number of 1
2. Logical operations (conditions, etc.)
> means greater than
>= greater than or equal to
== equal to (general checks such as the user's login is not equal to the condition)
!= is not equal to
&& and and (and)
|| or or (or)
xor mutually exclusive (Xor)
! Not (Not)
Other symbols
3. Other operations
$ variables (used many times)
& indicators of variables (added before variables)
@ do not display error messages (added before functions)
Examples

Copy code The code is as follows:

@include("dbx.txt"); / /If dbx.txt does not exist, an error will be reported, but it will not be displayed after adding @!
echo "
n";
?>

-> The method or attribute of the object
=> The element value of the array
?: Three far operators


Just remember the above, (But it’s not that easy to remember, haha!)
The higher-level ones are introduced below, which are also the more commonly used and key ones when writing programs!

1. Single-line if (judgment)
if. ..else...
If...what, what...what will be the result...responsible...how...
If...you are fat...you are a piglet... Otherwise... you are a skinny monkey.
if(conditon) { statment1} true
else {statment2} false false
Example:

$a = 4.998;
if($a > 5) //No semicolon is needed here, pay attention!
{
echo "Yes! a > 5n";
}
else       // No semicolon is needed here, pay attention!
                                                                                                                                                   



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truehttp: //www.bkjia.com/PHPjc/319111.htmlTechArticleToday we have reached a new level...Write first: (adding numbers) Copy code code As follows: ?php $a="10";//"Connect" the right side to the left side $a+="2";//"Add" the right side to the left side echo$a."brn";//The result here is. ..