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Output of all variables in php. PHP variable scope. Everything you wanted to know but were afraid to ask. Static variables: they are somewhere nearby

Php variables is a kind of information container that can contain Various types data (text, numbers, arrays, and so on). In general, variables allow you to create, store, modify, and in the future quickly access the information specified in them.

How to create a variable in PHP

Initially, the variables contain the sign $ (dollar) - designation of the use of a variable, then letters Latin alphabet(from a to z and small and large), at the end can contain numbers... Also, the name is allowed to use an underscore (not at the end).

How the variables can be named:

$ var
$ variable
$ year1945
$ _variable
How variables can not be called:

$ 1 - consists only of a digit
$ 1var - you cannot start a variable name with a digit
$ / var - only underscores are allowed of additional characters _
$ variable - Cyrillic allowed by php documentation but not recommended
$ var iable - spaces cannot be used

Each variable is assigned a value. To assign a value, use the sign = (equals). During the processing of the script, the value of the variable can change repeatedly depending on different conditions.

$ city = "Moscow"; // the variable $ city was assigned a string (in quotes) value Moscow
$ year = 1147; // and the $ year variable was assigned the numeric value 1147
?>

$ name = "Alexander";
$ Name = "Alexey";
echo "$ name, $ Name"; // displays "Alexander, Alexey"
?>

PHP Variable Output

Separately, you should consider how to display variables using output operators, the work of which we examined in the last lesson, Creating a PHP page. Output operators. ... Below I will give a number of illustrative examples with comments.

// This is how we assign values ​​to variables
$ name1 = "Alexey";
$ name2 = "Alexander";

// Display variables
echo $ name2; // Output: Alexander
echo "name1 is $ name1"; // name1 is Alexey

// When using single quotes, the output is
// variable name, not value
echo "name1 is $ name1"; // prints: name1 is $ name1

// you can simply display the values ​​of variables
echo $ name1; // Alexey
echo $ name1, $ name2; // Alexey Alexander
echo $ name1. "". $ name2; // Alexey Alexander
echo "$ name1, $ name2"; // Alexey, Alexander

Echo<<This uses the "here document" syntax to output
multiple lines with $ variable substitution.
END;

PHP Variable Operations

Arithmetic operations in PHP
In the case of numerical values, you can perform arithmetic operations: addition, subtraction, multiplication, and so on.

- $ a(negation) Change the sign of $ a.
$ a + $ b(addition) The sum of $ a and $ b.
$ a - $ b(subtraction) Difference between $ a and $ b.
$ a * $ b(multiplication) The product of $ a and $ b.
$ a / $ b(division) The quotient of $ a divided by $ b.
$ a% $ b(modulo division) The integer remainder of $ a divided by $ b.
Let's look at examples

$ a = 2; // note, in the case of numbers, quotes are not used
$ b = 3; // note, in the case of numbers, quotes are not used

$ result = $ a + $ b; // add variables
echo $ result; // will print 5

$ result = $ b - $ a; // add variables
echo $ result; // will output 1

Increment and decrement operations in PHP
These operations will be useful mainly when constructing loops, which we will talk about a little later.
Prefix- operators written BEFORE the variable ( - $ a; ++ $ a). Returns the value of the variable before the change.
Postfix- operators written after the variable ( $ a--; $ a--). Returns the modified value of the variable.
Increment- increasing the value.
Decrement- decreasing the value.

++ $ a Prefix increment. Increments $ a by one and returns the value of $ a.
$ a ++ Postfix increment. Returns the value of $ a and then increments $ a by one.
- $ a Prefix decrement. Decreases $ a by one and returns the value of $ a.
$ a-- Postfix decrement. Returns the value of $ a and then decrements $ a by one.
echo "

Postfix increment

";
$ a = 5;
echo "Should be 5:". $ a ++. "\ n";

Echo "

Prefix increment

";
$ a = 5;
echo "Should be 6:". ++ $ a. "\ n";
echo "Should be 6:". $ a. "\ n";

Echo "

Postfix decrement

";
$ a = 5;
echo "Should be 5:". $ a--. "\ n";

Echo "

Prefix decrement

";
$ a = 5;
echo "Should be 4:". - $ a. "\ n";
echo "Should be 4:". $ a. "\ n";
?>

PHP assignment operations
Basic operator looks like = ... At first glance, it may seem that this operator is equal. In fact, this is not the case. In effect, the assignment operator means that the left operand is set to the value of the right expression, (that is, it is set to the resulting value). Combined operators- these are operators that allow you to use the previous values ​​of variables for subsequent operations (append to a string variable (with text) or add numeric values).

$ a = ($ b = 2) + 4; // result: $ a is set to 6, $ b is set to 2.

$ a = 2;
$ a + = 3; // sets $ a to 5, similar to writing: $ a = $ a + 3;
$ b = "Hello";
$ b. = "Peace!"; // sets $ b to "Hello World!" as does $ b = $ b. "There!";

There are also comparison operations and brain teaser, but we will talk about them in the next lessons. I will try not to frighten you with a large amount of information right away!)

Continuing the previously asked question with new details. So: Site in the cloud, theme - Default 3.0, can_use_smarty = true On the product subpages, the Smarty code works quite well, it is possible to access and display the necessary variables. In the product description ...

Hello. In the checkout.html file there is a variable $ cart_total = $ wa-> shop-> cart-> total () it stores the final cost. And how to break this cost into the cost of delivery and the cost of the order and bring it all to the site? Thank you.

There is a solution

Good afternoon. Tell me, pliz. I have several product ids. For example, 1,3,5. I want to get data from $ wa-> shop-> product () on them. I need to assign a variable to the product data for these 3 IDs. How to do it? Not strong at ...

Something like this (I write from memory, I need to check) ($ all_my_products = $ wa-> shop-> products ()) (foreach $ all_my_products as $ ab) 

($ ab | var_dump)
(/ foreach)

I want to display 3 prices for a storefront at the same time There is a solution

Hello! There are 3 standard prices in IM: Purchase, Strikethrough and Retail. Also, with the help of the Multi-price plugin, I have created 2 more additional prices Wholesale, Dealer. It is necessary for all 3 prices to be reflected for all buyers, but when the client ...

The question is closed - the guys are already doing it.

What query can you display a list of available variables There is a solution

Tell me what you can use in development besides (debug) and (wa_dumpc ($ order)) to view the available variables on the page, and so on ... What constructs and queries can you use in development?

(wa_tpl_vars) - Helper that allows you to display all the variables passed to the current template .... this question has already been discussed.

There is a solution

Hi, I don’t understand anything in php, there is only general concept, about loops, arrays, etc. I use css, html, bootstap, uikit, because I don’t understand the framework, I can’t use it to its fullest I don’t understand how actions work, and where to get them (like ...

Look at the description of the Smarty template engine. Variables are passed to the template, which are generated and given to the user. To find out what is contained in a variable, you can output it separately ($ post | wa_print_r) (foreach $ post.plugins.before as $ plugin => $ output) ($ output) (/ foreach) Using this code, get an array from the $ post.plugins.before variable that contains the key ($ plugin) and the value ($ output). Output all the values ​​($ output) to the page.

+1 Not accepted

Variables from the Cheat Sheet do not work when inserted into Order Notifications, as well as into your printable order form ...

Refinement of the Default 2.0 theme

It is necessary to make some design improvements Default 2.0 1. Align the height of product images in the categories https: //yadi.sk/i/JazqloIg3ZQU ... 2. Change the output brief description, display additional fields with icons ...

Hello! Please tell me how to display the characteristics of the goods in the basket and in the catalog (list of goods), which are selected manually, for example, size? 1) There is already a selected value in the basket. Standard template file (product.cart.html) .2) In the product list ...

Please help me figure it out. Where to find more complete documentation on the engine. Namely, I am interested in all the smarty variables, how can I guess with what code I should display the product catalog, cart, product picture, characteristics, etc. and...

There is a solution

Good afternoon. There was a need to make several drop-down menus. Design theme Design with taste PRO I climbed into the sidebar / nav.html, by duplicating the code I was able to get the second menu, but since it is identical, naturally began to rule it. As soon as I ...

You can make a simple drop-down menu without even copying parts of the code associated with the scripts of the design theme, but create your own menu. Here is the script (paste it into the theme template) 350ms is the appearance time, and if you wish, you can add more different effects. Then you create two objects of classes open and menu

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