PHP Tutorial - Variables
PHP Tutorial - Variables
If you have never had any programming, Algebra, or scripting experience, then the concept of variables will be a new to you.
A variable is a means of storing a value, such as text string "Hello World!" or the integer value 4. A variable can then be reused throughout your code, instead of having to type out the actual value, over and over again.
In PHP you define a variable with the following form:
- $variable_name = Value;
If you forget that dollar sign at the beginning, it will not work. This is a common mistake for new PHP programmers!
<?php
$sentence = "This is a sentence.";
$price = 42.99;
$weight = 185;
?>
Say that we wanted to store the values that we talked about in the above paragraph. How would we go about doing this? We would first want to make a variable name and then set that equal to the value we want. See our example abow for the correct way to do this.
Note for programmers: PHP does not require variables to be declared before being initialized.
PHP Variable Naming Conventions
There are a few rules that you need to follow when choosing a name for your PHP variables.
- PHP variables must start with a letter.
- PHP variables may only be comprised of alpha-numeric characters and underscores. a-z, A-Z, 0-9, or _ .
- Variables with more than one word should be separated with underscores. $my_variable
Simple Example
$sentence = "This is a sentence.";
$price = 42.99;
$weight = 185;
print $sentence ."\n";
print $price ."\n";
print $weight ."\n";
?>