C Language Fourth Chapter

The essence of a program is to process data

Now that we know how to use variables to refer to data, when used, variables must be associated with the data in order to really play the role of the variable.

To solve this problem, the C language provides an operator, which is called an expression, such as age=23

Age is a variable, = is an operator, and 23 is data.

Complement: The meaning of the compound operator:

such as + =

The compound operator is not just for simplifying the expression of an operation, but the efficiency is where the compound operator comes in, such as

i=i+2;

i+=2;

The former used two times I, and then only used once, which leads to the latter's efficiency is one times the former.

The meaning of the self-increment decrement operator appears:

Maybe you would like to think it is not +1-1 well, ditto is also to increase efficiency, said the professional point is that we know that all the computer data calculation is done by the CPU (central processor), most of the CPU instruction system directly provides self-increment self-reduction command, so do not need you indirectly +1- It's 1.

The level of the programmer is the beginning of a work can be achieved, if the work can be achieved compared to efficiency.

Finally, let's talk about the readability of the program:

Because your own code is usually to maintain itself, and the maintenance cycle is often more than one months, imagine, when you see your code six months ago, and do not understand the time is comfortable in a sense.

C Language Fourth Chapter