Casting is a way to take a liquid and mold it int… oh yeah
So casting is just a fancy way to refer to type conversion, that is where you change the "type" of a variable from one thing to another. For example changing a string to an integer.
How about some examples? Is that what you want?
OK, fine, you talked me into it. Here are some PHP examples:
$var = '1000'; var_dump($var); // Returns string(4) "1000" $var = '1000'; $var = (int)$var; // Here is where we cast it var_dump($var); // Returns int(1000)
So, who cares? What's the point?
Well, depending on what you're wanting to do, it's important to change the type, and this is especially true in languages where there is no dynamic typing (like C#) and it's still useful in languages with dynamic typing like PHP, because it allows for one to avoid potential issues with mathematics, concatenation, etc. Aside from math related things, in PHP I use (int) a lot to clean up variables for SQL queries for both safety and also so MySQL doesn't have to convert the types itself.
You can learn more about type casting in PHP specifically and why it's a great way to do certain things here: Casting int faster than intval in PHP.