All we need to make the program more useful is to have a way to allow the user to provide input to the program. The scanf function is the counterpart to the printf function, except that scanf allows input to come from a user.
Note: The major difference between printf and scanf is, In printf() we pass variable values whereas in scanf() we pass the variable address.
The scanf() function is a commonly used input function in the C programming language. It allows you to read input from the user or from a file and store that input in variables of different data types.
As with gets , it is very dangerous to use scanf to read strings entered by the user, because scanf does not pay attention to the length of the typed strings, and it will admit a string longer than the size defined for the array into which that string is going to be saved.
The scanf() function can read input from keyboard and stores them according to the given format specifier. It reads the input till encountering a whitespace, newline or EOF. On other hand gets() function is used to receive input from the keyboard till it encounters a newline or EOF.
it is same or different function? scanf() considers an input upto whitespace, and gets() take upto a new line. Suppose the user input is "Hello World", gets() will take "Hello World" scanf() will take "Hello" puts() appends a new line after the string output, but printf() doesn't.
printf() - printf() returns the number of characters successfully written on the output. It is used to simply print data in the output. scanf() - It returns the number of data items that have been entered successfully.
The “%d” in scanf allows the function to recognise user input as being of an integer data type, which matches the data type of our variable number. The ampersand (&) allows us to pass the address of variable number which is the place in memory where we store the information that scanf read.
The problems with scanf are (at a minimum): using %s to get a string from the user, which leads to the possibility that the string may be longer than your buffer, causing overflow.
The printf() and scanf() functions are required for output and input respectively in C. Both of these functions are library functions and are defined in the stdio. h header file.
sprintf stands for "string print". In C programming language, it is a file handling function that is used to send formatted output to the string. Instead of printing on console, sprintf() function stores the output on char buffer that is specified in sprintf.
The printf functions create and output strings formatted at runtime. They are part of the standard C library. Additionally, the printf functionality is implemented in other languages (such as Perl). These functions allow for a programmer to create a string based on a format string and a variable number of arguments.
To convert the input, there are a variety of functions that you can use: strtoll , to convert a string into an integer. strtof / d / ld , to convert a string into a floating-point number. sscanf , which is not as bad as simply using scanf , although it does have most of the downfalls mentioned below.
printf() function is used for displaying output to the screen and in printf() function we use format specifiers like %c, %d, etc to detect the data type of variable which we give as input. Return type of printf function is integer. It returns the total no of characters given as output by printf().
With the sscanf() function in C, we can read (or extract) data from a string input. The sscanf() function is similar to the scanf() function, the only difference being that scanf() takes input from the console, while sscanf() takes input from a string (or a character array).
scanf: Reads formatted data from the standard input stream. scanf_s: Reads formatted data from the standard input stream. But safer than scanf (). scanf originally just reads whatever console input you type and assign it to a type of variable.
Inputting Multiple Values
If you have multiple format specifiers within the string argument of scanf, you can input multiple values. All you need to do is to separate each format specifier with a DELIMITER - a string that separates variables.
The scanf function reads input from the console and parses it. It has no means of printing anything.
The fscanf() function is used to read set of characters from file. It reads a word from the file and returns EOF at the end of file.
In C programming language, %d and %i are format specifiers as where %d specifies the type of variable as decimal and %i specifies the type as integer. In usage terms, there is no difference in printf() function output while printing a number using %d or %i but using scanf the difference occurs.
The difference is that when you use "%d " as format string, scanf() continues to consume white-space characters until it has encountered another non-white space character, like for example 2,3,4. A simply newline \n or another white space character after the input number won´t break the consuming.
%d (Decimal Integer) Format Specifier. %c (Character) Format Specifier. %f (Floating Point) Format Specifier.
Ans: The Limitations of scanf() are as follows: scanf() cannot work with the string of characters. It is not possible to enter a multiword string into a single variable using scanf(). To avoid this the gets( ) function is used. It gets a string from the keyboard and is terminated when enter key is pressed.
Printing has no effect on the ongoing execution of a program. It doesn't assign a value to a variable. It doesn't return a value from a function call.
scanf("%d", &b); The program will read in an integer value that the user enters on the keyboard (%d is for integers, as is printf, so b must be declared as an int) and place that value into b. The scanf function uses the same placeholders as printf: int uses %d.