Can PHP variables start with _?
_ usually means something private or internal. In C++ standard libraries all implementation specific variables must start with _ . In most languages, it doesn’t actually affect the functionality of the code, but is often used to denote reserved or internal names.
Can PHP variables start with numbers?
Variables in PHP are represented by a dollar sign followed by the name of the variable. The variable name is case-sensitive. Variable names follow the same rules as other labels in PHP. A valid variable name starts with a letter or underscore, followed by any number of letters, numbers, or underscores.
Do you have to initialize variables in PHP?
PHP does not require it, but it is a good practice to always initialize your variables. If you don’t initialize your variables with a default value, the PHP engine will do a type cast depending on how you are using the variable.
Why _ is used in C#?
The underscore before a variable name _val is nothing more than a convention. In C#, it is used when defining the private member variable for a public property. A lot of people use them for property private variables (the variables that actually store the values for public properties).
Why _ is used in Python?
The python interpreter stores the last expression value to the special variable called _ . The underscore _ is also used for ignoring the specific values. If you don’t need the specific values or the values are not used, just assign the values to underscore.
What is a valid PHP variable name?
A variable name must start with a letter or the underscore character. A variable name cannot start with a number. A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ ) Variable names are case-sensitive ( $age and $AGE are two different variables)
What is the correct way of declaring PHP variables?
Rules for declaring PHP variable:
- A variable must start with a dollar ($) sign, followed by the variable name.
- It can only contain alpha-numeric character and underscore (A-z, 0-9, _).
- A variable name must start with a letter or underscore (_) character.
- A PHP variable name cannot contain spaces.
Which is the correct way to start a single line PHP comment?
PHP Comment Syntax: Single Line Comment
To do a single line comment type “//” or “#” and all text to the right will be ignored by PHP interpreter.
What is the correct way to end a PHP statement?
As in C or Perl, PHP requires instructions to be terminated with a semicolon at the end of each statement. The closing tag of a block of PHP code automatically implies a semicolon; you do not need to have a semicolon terminating the last line of a PHP block.
How do you set a variable to null in PHP?
In PHP, a variable with no value is said to be of null data type. Such a variable has a value defined as NULL. A variable can be explicitly assigned NULL or its value been set to null by using unset() function.