Programming/Classes - Revision history

Brodriguez: Brodriguez moved page Classes to Programming/Classes

2020-10-25T17:26:06Z

Brodriguez moved page Classes to Programming/Classes

← Older revision	Revision as of 17:26, 25 October 2020
(No difference)

Brodriguez: Correct typo

2020-05-12T02:39:13Z

Correct typo

← Older revision		Revision as of 02:39, 12 May 2020
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	Conceptually, a class can be thought of as a grouping of logic and/or variables.		Conceptually, a class can be thought of as a grouping of logic and/or variables.

	Similarly, it can be ~~though~~ of as a [[Structs \| struct]] but with extra, included logic.		Similarly, it can be thought of as a [[Structs \| struct]] but with extra, included logic.

	== General Concept ==		== General Concept ==

Brodriguez: Add some lines

2020-05-12T02:32:19Z

Add some lines

← Older revision		Revision as of 02:32, 12 May 2020
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	}		}
	}		}

			Now, to access any of this logic, we can pass around a single instance of the class, which contains everything we need.<br>
			If we need additional values or logic, we can add new variables and methods to our class.

Brodriguez: Formatting

2020-05-12T02:24:59Z

Formatting

← Older revision		Revision as of 02:24, 12 May 2020
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	int revenue;		int revenue;
	int expenses;		int expenses;

	/**		/**
	* Logic to validate revenue.		* Logic to validate revenue.
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	}		}
	}		}

	/**		/**
	* Logic to validate expenses.		* Logic to validate expenses.
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	}		}
	}		}

	/**		/**
	* Logic to calculate and return profit.		* Logic to calculate and return profit.

Brodriguez: Create page

2020-05-12T02:24:27Z

Create page

New page

Conceptually, a class can be thought of as a grouping of logic and/or variables.

Similarly, it can be though of as a [[Structs | struct]] but with extra, included logic.

== General Concept ==
Hypothetically, let's say a business has a custom program. This program has a few "core" variables that are used throughout.<br>
We can call them {{ic | Revenue}}, {{ic | Expenses}}, and {{ic | Profit}}.

Let's also suppose that, in this program, any time one of the above variables is uses, the rest are guaranteed to be used shortly after.<br>
So far, this is identical to our [[Structs | struct]] page example.

Now let's add in a key difference. Imagine that we want special logic (functions) associated with these variables as well.

For example, maybe we don't want '''Profit''' to be a literal variable, per say, so much as we want it to be calculated as {{ic | Revenue - Expenses}}, every time it's called.<br>
Suppose we also want custom validation logic to make sure '''Revenue''' and '''Expenses''' are only positive numbers.

The easiest way to do this would be to encompass all of this into a class. Depending on the language, it may look something like this:
class Costs {
int revenue;
int expenses;

/**
* Logic to validate revenue.
*/
void set_revenue(int new_value) {
// Prevent revenue from being negative.
if (new_value <= 0) {
raise("Revenue cannot be negative.");
} else {
this.revenue = new_value;
}
}

/**
* Logic to validate expenses.
*/
void set_expenses(int new_value) {
// Prevent expenses from being negative.
if (new_value <= 0) {
raise("Expenses cannot be negative.");
} else {
this.expenses = new_value;
}
}

/**
* Logic to calculate and return profit.
*/
int profit() {
return this.revenue - this.expenses;
}
}