ProgIntro

Input Output Constructs

• For displaying data/information on the standard output (i.e. display screen) printf() function is used.

• See this program on how to use printf is a program that shows how to printf() is used.

• For taking input from standard input (i.e. keyboard) scanf() function is used.
• See this program on how to use scanf is a program that shows how to scanf() is used.
• both printf() and scanf() functions are provided by the standard input/output header <stdio.h>
• printf() function usually involves using escape sequences and format specifiers

Escape Sequences

• The backslash in \n is called the escape character.
• When the compiler sees a backslash in a string, it combines backslash with the next character to form an escape sequence
• The escape sequence \n means newline

Following table lists escape sequences and their description:

Escape Sequence	Description	Escape Sequence	Description	Escape Sequence	Description
\a	Alarm	\t	tab	\?	question mark
\b	backspace	\v	vertical tab	\000	octal number
\f	Form feed	\	backslash	\xhh	hexadecimal number
\n	new line	'	single quote	\0	Null
\r	carriage return	"	double quote

• See this program to understand how to use escape sequences

Format specifiers

• are used during the input or output
• scanf() function accepts 2 arguments
• 1st argument is a format control string, which indicates what type of data should be entered
• e.g. in scanf("%d", &numb) %d indicates that the data should be an integer

Following table lists the format specifiers and their description:

Format Specifier	Description
%d	Integer Format Specifier
%f	Float Format Specifier
%c	Character Format Specifier
%s	String Format Specifier
%u	Unsigned Integer Format Specifier
%ld	Long Int Format Specifier

• See this program to understand how to use format specifiers