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.
gets() is a pre-defined function in C which is used to read a string or a text line. And store the input in a well-defined string variable. The function terminates its reading session as soon as it encounters a newline character.
gets(buf); ... However, gets() is inherently unsafe, because it copies all input from STDIN to the buffer without checking size. This allows the user to provide a string that is larger than the buffer size, resulting in an overflow condition.
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.
In brief, scanf and getchar are two functions available in C language. The main difference between scanf and getchar is that scanf is a formatted way of reading input from the keyboard while getchar reads a single character from the keyboard.
getchar() in C is a function used to take the input of a single character from the standard input stream present in the stdin library. The getchar in C returns the unsigned char cast to the int value of the character it reads and does not take any parameter.
The C program uses scanf() to get the two resistance values and getchar() to select the circuit configuration. Problems can occur when using getchar() after scanf() due to new-line characters being stored in the keyboard buffer.
fgets. fgets() is a safer alternative to the gets() or scanf() function. It allows the developer to set the size of the buffer where the read data is stored.
Warning: The sprintf function can be dangerous because it can potentially output more characters than can fit in the allocation size of the string s . Remember that the field width given in a conversion specification is only a minimum value.
The problem is because of a certain feature of the scanf() function. When scanf() reads input from the standard input stream, it also creates a newline character in the buffer. So in the above code, after reading the integer x, the scanf() function left a newline character.
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.
So: gets is fundamentally unsafe. It's not just that it can be misused (the way, say, strcpy or C++'s std::copy can be misused); it's that it cannot be used at all without giving the user control over your process. Therefore, the function gets was removed from the C standard library in 2011.
The number of times you should use gets() in any program is zero.
Conclusion. In brief, gets and puts are two important C library functions. The difference between gets and puts in C Language is that gets is a function that reads a string from standard input while puts is a function that prints a string to the standard output.
The getline() function reads a whole line, and using the newline character transmitted by the Enter key to mark the end of input. The get() function is much like getline() but rather than read and discard the newline character, get() leaves that character in the input queue.
The sprint() function is present inside the C and C++ also. This function is used to store something inside a string. The syntax is like the printf() function, the only difference is, we have to specify the string into it. In C++ also, we can do the same by using ostringstream.
For a "safer" function, you could look at using snprintf where the size of the object is explicitly specified. Without specifying the size and using printf , you have to "trust" that the provided char* is a valid C-string with terminating null character, otherwise printf will keep reading the memory.
sprintf() function in C throws an exception when the size of the final formatted string after all the replacements exceeds the size of the buffer string. sprintf() function is the simplest method to convert the integer, float, character, and double value to a string value.
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.
str is already a pointer to first element in char array . So when you pass it to scanf you are already passing the address of the first element in array to scanf and thus no need of & to get the address.
The getch() in C is a function used in old operating systems to get user input. It only accepts one input character at a time or per the function call. It pauses the execution of the program until input is provided by the user. It doesn't use buffers to store the data and return the data as soon as the user enters it.
The primary difference between the getchar() and getc() is that the getc() is capable of reading from any input scheme, while the getchar() is capable of reading from the standard input. Hence, getchar() becomes equivalent to the getc(stdin). Here, Syntax: int getchar(void);
The getchar() function returns the ASCII value of the entered character. If the data type to which the result from getchar() will be stored is of type char, then the ASCII value will be converted to the corresponding character. If the data type is of type int, the values will be stored as ASCII values.
getch() it just gets an input but never display that as an output on the screen despite of us pressing an enter key. getchar() it gets an input and display it on the screen when we press the enter key. getchar() returns the character but doesn't display it.