Now a days, most of the students knows to develop a program using different technologies. But to be a professional programmer you need to follow some kind of ethics to develop an efficient software.
For example, you can write a simple (a+b) program in any number of lines.
But when you work in corporate for clients, you have to minimize the number of lines to reduce the size of the source program. And your program should take only minimum amount of compilation and execution time.
Also we have a lot of function for the same purpose with small difference. We need to understand every functions and use the efficient one.
To get the input from the user we have a many ways :
We are simply using scanf function to read the values from the user.
But every function from the above has different properties.
Like this, before/while developing a program we need to consider many things.