Is there a quick way to determine endianness of your machine? There are n no. Here is one quick way of doing the same. Since size of character is 1 byte when the character pointer is de-referenced it will contain only first byte of integer.
Does endianness matter for programmers? Most of the times compiler takes care of endianness, however, endianness becomes an issue in following cases. It matters in network programming: Suppose you write integers to file on a little endian machine and you transfer this file to a big-endian machine. Unless there is little endian to big endian transformation, big endian machine will read the file in reverse order. You can find such a practical example here. Standard byte order for networks is big endian, also known as network byte order.
Before transferring data on network, data is first converted to network byte order big endian. Sometimes it matters when you are using type casting, below program is an example. When I run above program on little endian machine, I get 1 as output, while if I run it on a big endian machine I get To make programs endianness independent, above programming style should be avoided.
What are bi-endians? Bi-endian processors can run in both modes little and big endian. What are the examples of little, big endian and bi-endian machines? Intel based processors are little endians. The lowest address of the four bytes is used for the address of a block of four contiguous bytes.
How is a bit pattern held in the four bytes of memory? There are 32 bits in the four bytes and 32 bits in the pattern, but a choice has to be made about which byte of memory gets what part of the pattern. There are two ways that computers commonly do this:. Big Endian Byte Order: The most significant byte the "big end" of the data is placed at the byte with the lowest address. The rest of the data is placed in order in the next three bytes in memory. In the end, that is why endianness is important; because not knowing how data is stored would lead to communicating different values.
This means that in order for you to use the Internet, your computer has to account for the difference in endianness.
As a reminder, little-endianness refers to the byte ordering where the least significant byte is stored first. So for example, if we have the 8-byte value of 0xabcdef0 we would store it in memory in the following way. Note: I put a pseudo memory address next to the values, this is so we can say that this value is at memory address 0x The most important thing to understand here is that we are storing an 8-byte value. On the other hand, if we were storing a 4-byte value, we would still flip the byte order, but just for those 4 bytes.
Take the following array as an example. This array, like the 8-byte number, takes up 8 total bytes and looks very similar.
However, in memory, we would not store the same thing as above, but instead the following:. Notice here how the order of the array is preserved and that the 0x value individually the first 4 bytes is in little-endian. Now, if we bring this back to big-endian, we can see that every one of these examples is stored in the same way. This is because big-endian is stored in the order that you see things. I would recommend proving this for yourself.
However counter-intuitive it might seem at first, there are valid reasons why little-endian is used over big-endian. The reason for the widespread use of little-endian is not because of the ease of user understanding as you might have figured out , but rather for ease of the computer. We will use this 8-byte value 0x When we store it in little-endian we have the following.
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