Variables in PHP start with the dollar sign
$, followed by an identifier, which is a set of alphanumeric chars and the underscore
A variable can be assigned any type of value, like strings (defined using single or double quotes):
$name = 'Flavio'; $name = "Flavio";
$age = 20;
or any other type that PHP allows, as we’ll later see.
Once a variable is assigned a value, for example a string, we can reassign it a different type of value, like a number:
$name = 3;
PHP won’t complain that now the type is different.
Variable names are case-sensitive.
$name is different from
It’s not a hard rule, but generally variable names are written in camelCase format, like this:
$ageOfDog. We keep the first letter lowercase, and the letters of the subsequent words uppercase.
I mentioned strings and numbers.
PHP has the following types:
boolboolean values (true/false)
intinteger numbers (no decimals)
floatfloating-point numbers (decimals)
nulla value that means “no value assigned”
and a few other more advanced ones.
We can use the
var_dump() built-in function to get the value of a variable
$name = 'Flavio'; var_dump($name);
var_dump($name) instruction will print
string(6) "Flavio" to the page, which tells us the variable is a string of 6 characters.
If we used this code:
$age = 20; var_dump($age);
int(20) back, saying the value is 20 and it’s an integer.
var_dump() is one of the essential tools in your PHP debugging toolbelt.
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