How to define php variables

How to define php variables?

PHP Variables

Variables are "containers" used to store information:

Example

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

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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