Why bitwise operators

This is used in Unix error codes. Also a n-bit bitmap can be a really cool and compact data structure. If you want to allocate a resource pool of size n, we can use a n-bits to represent the current status. Base64 encoding is an example.

Base64 encoding is used to represent binary data as a printable characters for sending over email systems and other purposes. Base64 encoding converts a series of 8 bit bytes into 6 bit character lookup indexes. Bit operations, shifting, and'ing, or'ing, not'ing are very useful for implementing the bit operations necessary for Base64 encoding and decoding.

I'm suprised no one picked the obvious answer for the Internet age. Calculating valid network addresses for a subnet. Bitwise operators are useful for looping arrays which length is power of 2. As many people mentioned, bitwise operators are extremely useful and are used in Flags , Graphics , Networking , Encryption. Not only that, but they are extremely fast.

My personal favorite use is to loop an array without conditionals. Suppose you have a zero-index based array e. By indefinitely I mean going from first element to last and returning to first. One way to implement this is:. This is the simplest approach, if you'd like to avoid if statement, you can use modulus approach like so:. The down side of these two methods is that modulus operator is expensive, since it looks for a remainder after integer division.

And the first method runs an if statement on each iteration. With bitwise operator however if length of your array is a power of 2, you can easily generate a sequence like So knowing this, the code from above becomes. Here is how it works. In binary format every number that is power of 2 subtracted by 1 is expressed only with ones. For example 3 in binary is 11 , 7 is , 15 is and so on, you get the idea.

Let's say we do this:. Is a number x a power of 2? Useful for example in algorithms where a counter is incremented, and an action is to be taken only logarithmic number of times. Which is the highest bit of an integer x? This for example can be used to find the minimum power of 2 that is larger than x.

Which is the lowest 1 bit of an integer x? Helps find number of times divisible by 2. But even then its speed boost over the modulus operation is negligible in my test on. NET 2. I suspect modern compilers already perform optimizations like this. Anyone know more about this? When you only want to change some bits of a microcontroller's Outputs, but the register to write to is a byte, you do something like this pseudocode :.

The value is 1 if the key is down before the message is sent, or it is zero if the key is up. They are mostly used for bitwise operations surprise. Here are a few real-world examples found in PHP codebase. I don't think this counts as bitwise, but ruby's Array defines set operations through the normal integer bitwise operators. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Real world use cases of bitwise operators [closed] Ask Question.

Asked 11 years, 9 months ago. Active 1 year, 7 months ago. Viewed k times. Improve this question. I remember when I first learned about them it seemed like they're used only for low-level c Can also use binary XOR to find a missing number in a permutation: martinkysel.

Add a comment. Active Oldest Votes. Those were just the first few examples I came up with - this is hardly an exhaustive list. Improve this answer. Hi Aaronaught, You have really shared a very good knowledge with us.

I am interested to know more about Bitwise Operator's real world cases. Would you mind sharing your reference with us, would be really helpful to read about it more. Are bitwise operations useful for vectorizable calculations? To extend the graphics part "a bit" lol , games devloppers frequently use bitwise operators to optimize perfomances, because there is a lot of mathematical operations, especially in physics engines, 3D engines, lightning on a scene, etc Is it odd?

Let us write a program to demonstrate the use of bitwise shift operators. After performing the left shift operation the value will become 80 whose binary equivalent is After performing the right shift operation, the value will become 5 whose binary equivalent is It is a unary operator. If we have an integer expression that contains then after performing bitwise complement operation the value will become Skip to content.

What are Bitwise Operators? Report a Bug. Previous Prev. Next Continue. Home Testing Expand child menu Expand. SAP Expand child menu Expand. Web Expand child menu Expand. Likewise, the SIMD may only support parallel 8-bit addition, without implementing addition for wider elements such as bit, bit or bit. To emulate them, one needs to extract the sign bit from the 8-bit calculation result, then perform the carry operation on the next element. Packing data, quicker ops multiplication, division, and modulus are significantly faster if aligned to powers of 2 , bit flipping, etc.

Learn them and start using them and you'll slowly start to see most of the advantages on your own. Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. What are the advantages of using bitwise operations? Asked 11 years ago. Active 8 years ago. Viewed 28k times.

Improve this question. Add a comment. Active Oldest Votes. Improve this answer. For those interested in more boolean bit operations and optimizations, have a look at Hacker's Delight: amazon. C1 E9 Modern compilers will do that for you. I think using bit-wise operators are more about readability these days. For example, you can distinguish encoding of a character using their first bits. NET has the [Flags] attribute which allows using an Enum as a bit field.