OFFSET in Computer Science

OFFSET in Computer Science

In the post, We will understand what is the meaning of OFFSET in computer science with an example.

In computer science offset comes picture at may place like packing a data structure, encoding the data etc in some standard protocol so that other parties can deserialise it and understand the data. We will understand its important how does it work with example. suppose we have a data structure for a student like

 {  
 name:string[20]  
 roll: int[4]  
 course: string[25]  
 batch: int[4]  
 }  

We want to serialise below student data 

 {  
 name:"Amit Gupta"  
 roll: 1234  
 course:Computer Science"  
 batch: 2018  
 }  

Our protocol follow the rule that we will insert a value and if space will remain empty we will fill it with $ for example length of "Amit Gupta" is 10 but standard size is 20 so will fill 10 $ after "Amit Gupta". So serialisation of above data will be

 Amit Gupta$$$$$$$$$$1234Computer Science$$$$$$$$$2018  

So according to our data structure

• OFFSET of name will be zero and length will 20
• OFFSET of roll will be 20 and length will 4
• OFFSET of course will be 24 and length will 25
• OFFSET of batch will be 49 and length will 4

So from above you can clearly say that OFFSET of any variable or character is number of character before it.

Now for example we can encode it into base64 before sending it third party. So base64 encoding of above string will be

 IEFtaXQgR3VwdGEkJCQkJCQkJCQkMTIzNENvbXB1dGVyIFNjaWVuY2UkJCQkJCQkJCQyMDE4ICA=  

Other can decode it and now he know how to deserialise because of protocol definition from 0 to 20 character he will consider as name and ignore the $ symbol next 20 to 24 as roll, 24 to 49 as course and 49 to 53 as batch.


Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.