Input & Output

Objective #1: Be able to display output in C.

• The printf function can be used to display output.
  
  
• Type the following code:
  
  #include <stdio.h>
  
  void main()
  {
     printf("hello world\n");
  }
  
  
• Here is another example:
  
  #include <stdio.h>
  
  void main()
  {
     int a = 10;
     double b = 3;
     char name[] = "Bill";
     printf("%s, the answer to %d + %lf = %lf\n", name, a + b);
  }
  
  Be sure to use %lf with double variables and %s with character arrays.
  
  
• Here is another example
  
  

  #include <cstdio.h>
  
  
  
  int main()
  {
  	char lastName[10];	// 9 letters or less
  	int i = 0;
  	char wholeName[80];
  
  	printf("Enter your last name: ");
  	scanf("%s", lastName); 
  	printf("Your last name is %s\n", lastName);
  	printf("Enter your age: ");
  	scanf("%d", &i);
  	printf("Mr. %s, %d years old.\n", lastName, i);
  	printf("What is your whole name?");
  	gets(wholeName);
  	printf("Goodbye, %s\n");
  
  	return 0;
  }     

Objective #2: Be able to obtain input in C.

• The scanf function can be used to obtain numeric and text input.
  
  
• Here is an example:
  
  #include <stdio.h>
  
  void main()
  {
     int a = 10;
     double b = 3;
     double answer = 0;
     char name[20];
     printf("Enter your name, an integer, and a decimal value: ");
     scanf("%s", &name);
     scanf("%d", &a);
     scanf("%lf", &b);
     answer = a + b;    
     printf("%s, the answer is %lf\n", name, answer);
  }