1#include <stdio.h>/*is a pre-processing command, its role is to inform the C compiler system in the C program before the formal compilation needs to do some preprocessing work. */2 intMain ()The /*c program executes the code in the main function, or it can be said that the main function is the only entry in the C language. */3 {4printf"I Love imooc!");/*See if the print statement here is correct*/ 5 return 0;6}
Two: Data type
1 #include <stdio.h>2int main ()3{4 int age=; /* define the age variable */5 printf (" I am%d this year!") \ n", age); 6 return 0 ; 7 }
C Language Support data types
Formatted output
1#include <stdio.h>2 intMain () {3 intAge = -;4 floatHeight =1.85;5 CharUnit ='m';6printf"Xiao Ming is%d years old \ n", age);7printf"Xiao Ming's height%f%c\n", height, unit);8printf"Xiao Ming is now learning it technology on the Internet in MU class"); 9 return 0;Ten}
Defining constants
1#include <stdio.h>2 3 #definePocketmoney 10//defining constants and constant values4 intMain ()5 {6 //Pocketmoney = 12; //does Xiao Ming increase his pocket money privately? 7printf"Xiaoming got%d dollars in pocket money again today \ n", Pocketmoney);8 return 0; 9}
Automatic conversion type
1#include <stdio.h>2 intMain ()3 {4 Charc ='a';5 intn = C;//Assign c to n6 floatf = C;//Assign c to f7 DoubleD = C;//Assign c to D8printf"%d\n", n);9printf"%f\n", f);Tenprintf"%lf\n", d); One return 0; A}
Forced conversions
1 #include <stdio.h>2 int Main () 3 { 4 double num = 2.5 ; // 5 printf ( " num is%d\n , (int ) NUM); Cast to int output 2 6 return 0 ; 7 }
Three: operator
Note In the division operation:
If the two digits of the division are integers, then the result is an integer, the fractional part is omitted, such as 8/3 = 2, and two is a decimal , and The result is a decimal number, such as: 9.0/2 = 4.500000.
Take note of the remainder operation:
This operation is only suitable for two integers , such as: 10%3 = 1, while 10.0%3 is wrong; The post-op symbol depends on the symbol being modulo, such as (-10)%3 =-1; and 10% (-3) = 1.
Note: The C language does not have the exponentiation operator, nor can it use arithmetic symbols such as x,÷.
Assignment Operators
+ =,-=, *=,/=,%=
Comparison operators
logical operators
Trinocular operator
1#include <stdio.h>2 intMain ()3 {4 //define the money in the small pocket5 DoubleMoney = A ; 6 //define the cost of a taxi home7 DoubleCost =11.5 ; 8printf"Small series can take a taxi home:"); 9 //Output y small series on a taxi home, output n Small series can not take a taxi homeTenprintf"%c", Money>cost?'y':'N' ); One return 0; A}
One: C language (data types and operators)