![]() When the Data Encryption Standard algorithm, also known as the DES algorithm, was formed and standardized, it made sense for that generation of computers. In the process, we'll learn about some use cases for bit manipulation in the real world.Why Was the AES Encryption Algorithm necessary? In the next lesson, we'll learn more about bit manipulation, including JavaScript operators for manipulating bits. Note that we have to put parentheses around the number or the parser will get confused and throw the following error: Uncaught Synta圎rror: Invalid or unexpected token. Because the binary number system is base 2, we can convert a decimal number to binary like this: > (34).toString(2) This method turns a number to its string equivalent - but we can also specify an optional base as an argument. We can also convert any number into its binary equivalent with the () method. This will allow us to explore use cases for bitwise manipulation in the next lesson. ![]() Now that we know the basics of bits and bytes and have also covered the basics of the binary number system, let's look at some methods we can use with binary numbers. Terabyte: 1024 gigabytes (approximately one trillion bytes).Gigabyte: 1024 megabytes (approximately one billion bytes).Megabyte: 1024 kilobytes (approximately one million bytes).Kilobyte: 1024 bits (approximately 1000 bytes).Here's how they all correspond to each other: Sometimes we might even talk in terms of terabytes. We now tend to measure things in terms of megabytes (say, a music file) and gigabytes (the storage space in our hard drive). Of course, processing power is much more advanced now. It's not because 255 is a nice-sounding number - it's because that is the total number of permutations of rupees that can be stored in a single byte (ranging from 0 to 255) - and back then, game systems did not have the processing power that they do now. For example, in the original Legend of Zelda on the Nintendo Entertainment System, you can only have up to 255 rupees, the currency of the game. Also, if you've ever played an old Nintendo video game, the max value of a stat or thing you can hold is often 255. It's no coincidence that there are 255 characters represented in the extended set of ASCII character codes. A byte consists of 256 different combinations if you include the number 00000000 - all the binary numbers between 0000001111.Ī single byte is an excellent option for storing characters. In general, for each bit we add to a sequence, we have double the number of total possible permutations:Ī group of eight bits put together is known as a byte. Fortunately, a computer can look at lots of transistors all at once in order to count.Įach 0 or 1 in a sequence of binary code is a bit. If we want to extend the metaphor, we can think of a transistor as having two fingers - it can only count to two. Some cultures (such as the Mayans) even had a base 20 system (counting on both fingers and toes). If we all had 8 fingers, we'd likely use the octal system, and if we had 12, we'd probably use the duodecimal system. Humans most likely use a decimal system because we (usually) have ten fingers to count on. The 1 represents the on state while the 0 represents the off state. Why does a computer use binary language? Well, at the very deepest level, a computer's processing power consists of billions of transistors that have only two states: on and off. When we get to the number 1, we have to add a new digit and start over. The binary number system is base 2, which means it only uses two digits: 0 and 1. The same pattern happens when we switch from 99 to 100, 999 to 1000, and so on. To get to the next number, we add an extra digit to the beginning and start over. When we are counting up, we hit the end of these digits when we reach 9. Humans generally use the decimal number system, though. For example, an uppercase A translates to 01000001 in binary code. Computers use the binary number system, but what exactly does that mean? At this point, we should all recognize a number that's using the binary number system - it's just a series of zeroes and ones.
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