1. The basic format of
the include <stdio.h>
int main () {
return 0;
}
2. Data type
int, float, double, char
Example: A char = 'A';
A + A = 32; or a + = 32; // a = 'a'; legitimate statement.
3. Output statement
printf ( "Helloworld \ n") ; // \ t spaces, \ n is newline.
Output with the output statement int, float, double, char data type.
printf ( "a =% d, b =% f, e =% c"); //% d is an integer type,% f as a decimal type (float, double),% c as char type ( 'a', ' B ').
Output String:
`` `
#include <stdio.h>
int main () {
char STR [] =" http://c.biancheng.net ";
the printf ("% S \ n-", STR); // output by name as a string
printf ( "% s \ n" , "http: //c.biancheng.
puts ( "http://c.biancheng.net"); // direct output
return 0;
} // the puts () and gets () method designed to handle strings.
`` `
4. scanf input statement int, float, double, char data type.
int A, B;
Scanf ( "% D,% D", & A, & B);
a float type
a float A, B;
Scanf ( "% F,% F", & A, & B);
Double type
Double A, B;
Scanf ( "% LF,% LF", & A, & B);
char type
char A, B;
Scanf ( "% C,% C", & A, & B);
5.putchar () statements, getchar () statement
Example: char a, B, C;
a = getchar ();
the putchar (a);
the putchar ( '\ n-');
6. the definition of the constants
const int a = 100; // if a on the left side of the assignment operator, will be given .
7. definition array
int a [100]; // define a 100-element array of type int
Note: If the array definition, and specifies the initialization of the array length and which do not being initialized array elements, the system automatically defined as 0, (defined as the character '\ 0', defined point type is NULL, i.e., null pointer). Note: When the size of the array of arrays can not be defined as a variable.
EXAMPLE error: n-int;
Scanf ( "% D", & n-);
int A [n-];
8. The defined character string
char = C 'C';
char STR [] = "Happy the I AM"; // etc. It is equivalent to: char str1 [] = { ' I', '', 'a', ',' 'm', '', 'h', 'a', 'p', 'p', 'y', '\ 0'}; ( '\ 0' to the end of the flag)
new string for the old string (for the new shorter than the old, if the new Bi-old long without a problem) ** "C programming" P158.
A = char "Happy the I AM";
A = { 'C', 'H', 'A', 'R & lt', '\ 0'} // '\ 0' is at the end, after all no longer showed (not output)
1. Select statement example switch-case # include <stdio.h>
main int ()
{
int type;
Scanf ( "% D", & type);
/ * IF (type ==. 1)
the printf ( "Hello");
the else IF (type == 2)
the printf ( "Good morning") ;
the else IF (of the type == 3)
printf ( "good evening");
the else IF (of the type == 4)
printf ( "goodbye");
the else
printf ( "ah, ah?");
return 0; * /
/ / -------------------------------------------
Switch (type) {/ / type must be of type int
Case 1:
printf ( "Hello");
BREAK;
Case 2:
printf ( "good morning");
BREAK;
case 3:
printf ( "Good evening");
BREAK;
Case 4:
printf ( "Goodbye");
BREAK;
default:
printf ( "? ah, ah");
}
return 0;
} 2. prime - control loop #include < stdio.h>
int main () {
int x;
Scanf ( "% D", & x);
int I;
int = the isPrime. 1;
for (I = 2; I <x; I ++) {// x where the maximum occurring as 'x-1', is not X
IF (% I X == 0) {
the isPrime = 0;
BREAK;
}
}
IF (the isPrime ==. 1) {
the printf ( "is a prime number \ n-");
} the else {
printf ( "Is not prime \ n-");
}
return 0;
}
