N, that's not too much trouble to change, more than 3000 lines, that's not dizzy ~ if you define a # define in advance.
n
Constant value', so when you want to modify the constant value inside the program, just modify the constant value after n, which is equivalent to changing the same constant value inside the program, which is very convenient.
The quantity whose value can be changed in the process of program execution is called variable, and the types of variables are divided into system variables and user-defined variables. In fact, user-defined variables have the same meaning as system variables. When you learn structured programming, you will understand the meaning of custom variables. There are four kinds of system variables: int integer variable, stored by users, accounting for 4 bytes; Float single-precision floating-point type, which is used to store the value of decimal point, accounting for 4 bytes; Double high-precision floating-point type, compared with float, double decimal is more accurate, accounting for 8 bytes; Char character variable, which mainly stores letters, and its size accounts for 1 byte. For example, "# define"
n
What does this sentence mean in 10 "C language?
N= 10。 In the following procedure, the number 10 can be represented by n.
This is a macro definition, which means that all n variables appearing in the program are assigned to 10. To correct it again, in macro definition, capitalization is generally used. To be precise, # definition
n
10 "does not mean n= 10.
Instead, use 10 instead of n, which is different.
Example: #include
# Definition
n
a+b
empty
main(){int
a= 1，b = 2；
Print function
(" %d "，n * 5)； The output is 1 1 instead of 15.
Another example is:
# Including
# Definition
n
(a+b)