Code C

1. Data Format String
- %c : Character
- %s : String
- %d : Sign decimal Integer
- %f : Decimal floating point
- %u : unsigned decimal integer
- %x : unsigned hexa integer

2. Handle input/output
a. function getc(FILE *stream)
- in stdio.h library
- get the next character from the specified stream
- Declaration : getc(FILE *stream); 
   + parameters: stream -- this is pointer to a FILE object identify the stream on which operation is to         be performed.
- Example :

 #include <stdio.h>

int main() {
int ch;
printf("Please type one charecter \n");
ch = getc(stdin);
printf("This is charecter type from key-broad: %c", ch);
return 0;
}

b. fuction getchar()
- Return numeric value of character read. If an end-of-file or error occurs, function return EOF.
NOTE :
getc(stdin) = getchar()

- Example :
int main() {
printf("=====================================================\n");
printf("function getchar()\n");
int ch1,ch2;
printf("Please type two character : \n");
ch1 = getc(stdin);
ch2 = getchar();
printf("this is character type ch1 : %c \n",ch1);
printf("this is character type ch2 : %c",ch2);
return 0;
}

c. function putc()
- Write a character to the specified file stream.
- Declaration :  int putc(int c, FILE *stream);
   + int c : the output is a character saved in Integer variable c.
   + FILE *stream : specifies a file stream.

3. Pointer
- pointer variable contain  the memory address of another variable.
 e.x

#include <stdio.h>
#include <stdlib.h>

/*
 * 
 */
int main() {
    char c;
    int x;
    float y;
   
    printf("c : address = %p, content = %c\n", &c,c);
    printf("x : address = %p, content = %d\n", &x,x);
    printf("y : address = %p, content = %f\n",&y,y);
    
    c = 'A';
    x = 10;
    y = 20;
    
    printf("c : address = %p, content = %c\n", &c,c);
    printf("x : address = %p, content = %d\n", &x,x);
    printf("y : address = %p, content = %f\n",&y,y);
    return 0;
}

- declaring pointer
         data-type *pointer_name;

         + data-type : type of data to which pointer point.
ex. 

  char c, *prt_c;
    int x, *prt_x;
    float y, *prt_y;
    
    c = 'A';
    x = 29;
    y = 69.96;
    
    printf("c : address = %p, content = %d\n", &c,c);
    printf("x : address = %p,content = %d\n", &x,x);
    printf("y : address = %p, content = %5.2f\n",&y,y);
    
    prt_c = &c;
    printf("prt_c : address = %p, content = %p\n", &prt_c, prt_c);
    printf("prt_c => %c\n",*prt_c);
    
    prt_x = &x;
    printf("prt_x : address = %p, content = %p\n", &prt_x, prt_x);
    printf("prt_x => %d\n", *prt_x);
    
    prt_y = &y;
    printf("prt_y : address = %p, content = %p\n", &prt_y, prt_y);

    printf("prt_y => %

Note : * value of memory address pointer point
           & address memory .


4. Array

- An Array is a collection of variables that are same data type.
- Decraling Array :

             data type  arrary_name[array size];

ex: int array_name[9];

- Index : index in array start from zero ( 0 < index < array_size)
- Initializing array :
    ex : int array_name[5] = {0,1,2,3,4};

example to initializing arrays:

  int array_int[10];
    int i;
    for (i = 0; i < 10; i++) {
        array_int[i] = random();
        printf("array_int[%d] = %d\n" ,i,array_int[i]);

    }


- Array and pointer : pointer point to first element of array
ex :

 int array_int[10];
    int *ptr_array;
    int i;
    for (i = 0; i < 10; i++) {
        array_int[i] = random();
    }

    ptr_array = array_int;
    printf("the start address of array_int is %p\n", ptr_array);
    printf("the value start element of array_int is : %d \n", *ptr_array);

    ptr_array = &array_int[0];
    printf("the start address of array_int is %p\n", ptr_array);
    printf("the value start element of array_int is : %d \n", *ptr_array);


- Multidimensional Arrays:

data-type name_array[array-size1][array-size2]......[array-sizen];

ex; 

 int array_int[3][5];

    for (int i = 0; i < 3; i++) {
        printf("\n");
        for (int j = 0; j < 5; j++) {
            array_int[i][j] = i + j * 5;
            printf("%6d",array_int[i][j]);
        }

    }