SOLID PRINCIPLES: Single Responsibility 💪👨‍💻

SOLID principles basically form the fundamental guidelines for building 

👉 object-oriented , 

👉 loosely coupled , 

👉 robust, maintainable and 

👉 easily understandable applications .

𝐀 𝐜𝐥𝐚𝐬𝐬 𝐬𝐡𝐨𝐮𝐥𝐝 𝐡𝐚𝐯𝐞 𝐨𝐧𝐞 𝐚𝐧𝐝 𝐨𝐧𝐥𝐲 𝐨𝐧𝐞 𝐫𝐞𝐬𝐩𝐨𝐧𝐬𝐢𝐛𝐢𝐥𝐢𝐭𝐲. 

We should write, change or maintain a class for only one purpose 

which gives us the advantage of cleaner ,robust code and 

fewer test cases as to we know which functionality is covered in which class and which class would be modified in case of a change. 

For ex:

𝑝𝑢𝑏𝑙𝑖𝑐 𝑐𝑙𝑎𝑠𝑠 Calculator{

𝑝𝑢𝑏𝑙𝑖𝑐 𝑣𝑜𝑖𝑑 𝑝𝑟𝑖𝑛𝑡𝐷𝑒𝑡𝑎𝑖𝑙𝑠() {}

𝑝𝑢𝑏𝑙𝑖𝑐 𝑑𝑜𝑢𝑏𝑙𝑒 𝑐𝑎𝑙𝑐𝑢𝑙𝑎𝑡𝑒() {}

𝑝𝑢𝑏𝑙𝑖𝑐 𝑣𝑜𝑖𝑑 𝑎𝑑𝑑𝑡𝑜𝐷𝐵() {}

}

Above class has three separate responsibilities: 

―printing, 

―calculation and 

―adding to database. 

By applying SRP, we can separate the above class into three classes with separate responsibilities.