Can this PHP code be valid: $4bears = $bears->getFirst4();

[ansharma]

Hi,

Can this PHP code be valid: $4bears = $bears->getFirst4();..

Can you please explain this ..Since the Answer i got is "Yes".

 

Thanks

 

[silkfire]

Yes it's valid. The -> notation specifies that you're using a function, getFirst4(), belonging to a class ($bears is a copy of this class), and that you want to assign the result of that function to your variable $4bears.

[trq]

getFirst4(), belonging to a class ($bears is a copy of this class)

 

$bears is an object, not a class. There is a difference.

 

No it is not valid. Variables cannot begin with a number. See $4bears

[ansharma]

is it possible to define a variable name starting with number?

like this $4xyz=5;

[trq]

No, did you not just read my previous post?

[ignace]

is it possible to define a variable name starting with number?

like this $4xyz=5;

 

Yes but only in the form:

 

${4xyz} = 5;

 

You also need to access it in the same way:

 

print ${4xyz};

 

As a side note: You should avoid writing variables like that.

[salathe]

is it possible to define a variable name starting with number?

like this $4xyz=5;

 

It's a valid variable name, in the sense that a variable can exist called "4xyz". However, it is not a valid label (the part that comes after $ to denote a variable). 

 

In other words, you cannot define a variable name like $4xyz but you can define it using the $GLOBALS superglobal variable ($GLOBALS['4xyz']) or a variable-variable ${'4xyz'}.

 

But... don't.

 

 

 

As a side note: You should avoid writing variables like that.

 

Mostly because it will generate a parse error.

[ignace]

This question raised my curiosity as to Why can't variable names start with numbers?

 

Apparently because:

 

It's likely a decision that came for a few reasons, when you're parsing the token you only have to look at the first character to determine if it's an identifier or literal and then send it to the correct function for processing. So that's a performance optimization.

 

Use of a digit to begin a variable name makes error checking during compilation or interpertation a lot more complicated.

 

Because if it did, it would be called COBOL.