What is the Difference Between scanf and getchar

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. 

C is a high-level, general-purpose programming language developed by Dennis Richie at Bell Labs. It is the foundation programming language of many other programming languages. C contains multiple header files. One of them is <stdio.h>. The header file provides functions to perform standard input and output operations. The programmer can use these functions in his program. Two of them are scanf and getchar.

Key Areas Covered

1. What is scanf
    – Definition, Functionality
2. What is getchar
     – Definition, Functionality
3. Difference Between scanf and getchar
     – Comparison of Key Differences

Key Terms

C, getchar, scanf

Difference Between scanf and getchar - Comparison Summary

What is scanf

The scanf function helps to read input from the keyboard and to store them according to the given format specifier. It reads input data until reading whitespace, newline or EOF. Refer to the below program.

Difference Between scanf and getchar

Figure 1: C program with scanf

In the above program, mark1 and mark2 are two integer variables. The printf command informs the user to enter marks. The scanf function helps to read input from the keyboard. As the inputs from the keyboard are integer values, the format specifier is %d.  If the input value is char, the format specifier is %c. Moreover, if the input value is a string, the format specifier is %s.  

The received input values are stored in the mark1 and mark2 variables. Therefore, the programmer has to send the address of those variable to the scanf function as in line 7. Finally, the printf statements display those values on the console.

What is getchar

The getchar function helps to read a character from the standard input. It waits until pressing the enter key. Then the user can view that reading on the console. As this function only works on the standard input, it does not require an argument. Refer to the below program.

Main Difference - scanf vs getchar

Figure 2: C program with getchar

In the above program, the printf function informs the user to end a character. The getchar function allows entering a value. When the user provides a character, it displays on the console and waits until the user press the Enter key. Then, the printf function displays that character on the console.

Difference Between scanf and getchar_Figure 3

Figure 3: Another C program with getchar

When observing the output of the above program, the user has entered four characters, but the getchar only reads one character and stores that in the “ch” variable. Finally, the printf function displays that value on the console.

Difference Between scanf and getchar

Definition

scanf is a C function to read input from the standard input until encountering whitespace, newline or EOF while getchar is a C function to read a character only from the standard input stream(stdin), which is the keyboard. Thus, this is the main difference between scanf and getchar.

Parameters

Furthermore, while scanf function takes the format string and variables with their addresses as parameters, the getchar function does not take any parameters. Hence, this is another difference between scanf and getchar.

Functionality

Moreover, how each of them function is an important difference between scanf and getchar. The scanf reads data according to the format specifier; it describes the data types the user sends through the keyboard. However, getchar reads a single character from the keyboard.

Conclusion

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. 

References:

1.Python Strings (With Examples), Available here.
2.“C Input Output (I/O).” Python Strings (With Examples), Available here.
3.“Getchar.” Cplusplus.com, Available here.

About the Author: Lithmee

Lithmee holds a Bachelor of Science degree in Computer Systems Engineering and is reading for her Master’s degree in Computer Science. She is passionate about sharing her knowldge in the areas of programming, data science, and computer systems.

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