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How to define php variables?
PHP Variables
Variables are "containers" used to store information:
Example
<?php $x=5; $y=6; $z=$x+$y; echo $z; ?>
Output:
11
Similar to Algebra
x=5 y=6 z=x+y
In algebra, we use letters (like x) and assign values to them (like 5).
From the above expression z=x y , we can calculate the value of z to be 11.
In PHP, these letters are called variables.
Lamp variables are containers used to store data.
PHP variables
Similar to algebra, PHP variables can be assigned a certain value (x=5) or an expression (z=x y).
Variables can have very short names (such as x and y) or more descriptive names (such as age, carname, totalvolume).
PHP variable rules:
Variables start with the $ symbol, followed by the name of the variable
The variable name must start with a letter or underscore character
Variable names can only contain alphanumeric characters and underscores (A-z, 0-9 and _)
Variable names cannot contain spaces
Variable names are case-sensitive ($y and $Y are two different variables)
lamp PHP statements and PHP variables are case-sensitive.
Create (declare) PHP variables
PHP has no command to declare variables.
A variable is created when you first assign a value to it:
Instance
<?php $txt="Hello world!"; $x=5; $y=10.5; ?>
Output:
Hello world!
In the execution of the above statement, The variable txt will hold the value Hello world!, and the variable x will hold the value 5.
Note: When you assign a text value to a variable, please add quotation marks around the text value.
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