Getchar Function In C

Syntax

int getchar (void);

It doesn't accept any arguments. Nonetheless, it outputs the characters read as an unsigned char within an integer, and in case of a file error, it returns EOF indicating the end of the file.

Now, we will create multiple programs that utilize the getchar function to receive single characters in the C programming language, and then display them using the putchar function.

Read a single character using the getchar function

Let's explore a program that reads a single character using the getchar function in the C programming language.

Program.c

#include <stdio.h>
#include <conio.h>	
void main()
{
	char c;	
	printf ("\n Enter a character \n");
	c = getchar(); // get a single character
	printf(" You have passed ");
	putchar(c); // print a single character using putchar

	getch();
}

Output

Enter a character
A
 You have passed A

In the program shown above, a user inputs a single character during runtime using the getchar function. Once the character is obtained, it is displayed using the putchar function.

Read n characters from the user using getchar function

Let's explore a program that reads n characters by utilizing the getchar function in the C programming language.

Getchar.c

#include <stdio.h>
#include <conio.h>
#include <ctype.h> 
int main()	
{
	char ch; 
	printf (" Enter a character ( If we want to exit press #) \n");
	while (ch != '#') /* accept the number till the user does not enter the # to exit from the loop. */
	{
		ch = getchar(); 
		printf (" \n We have entered the character : ");
		putchar (ch); // print a single character
		printf ("\n");
		}	
		return 0;
}

Output

Enter a character ( If we want to exit.. press #)
A

 We have entered the character: A
 We have entered the character:

B

 We have entered the character: B
 We have entered the character:
C

 We have entered the character: C
 We have entered the character:

In the displayed result, a while loop iteratively receives a character from the user until the user inputs the # character. In this scenario, the getchar method extracts a single character from the standard input and assigns it to a variable named ch. Meanwhile, the putchar function displays the retrieved character.

Read a single character using the scanf function

Let's explore a program that reads a character using the scanf function from the C library.

Prog.c

#include <stdio.h>
#include <conio.h>
int main()
{
	char ch;
	
	printf ("\n Enter the character \n");
	scanf ("%c", &ch); // get a single character, numeric or words
	printf( " You have entered %c",  ch);  /* It print a single character or first letter of the words. */

	return 0;
}

Output

Enter the character
A
 You have entered A

When running the aforementioned code, we observe that it captures either a single character or a sequence of characters through the scanf function as opposed to the getchar function. However, it's important to note a slight distinction; while scanf is capable of receiving either a single character or a group of characters from the user, getchar is limited to accepting only a single character.

Here we once more run the aforementioned program, and on this occasion, it displays the following outcomes.

Enter the character
Apple
 You have entered A

Read the characters using a do-while loop

Let's explore a program that reads characters by utilizing a do-while loop along with the getchar function in the C programming language.

Dowhile1.c

#include <stdio.h>
#include <ctype.h>
int main()
{
	int ch, i = 0;
	char str[150]; 
    printf (" Enter the characters from the keyboard (Press Enter button to stop).\n");
    // use do while loop to define the condition
    do
    {
    	ch = getchar(); // takes character, number, etc from the user
    	str[i] = ch; // store the ch into str[i]
    	i++; // increment loop by 1
	} while (ch != '\n');  // ch is not equal to '\n'
	printf("Entered characters are %s ", str); 
	return 0;
}

Output

Enter the characters from the keyboard (Press Enter button to stop).
Well b47gvb come
Entered characters are Well b47gvb come

In the provided code, a do-while loop iteratively receives characters from the user until the user presses the ENTER key to terminate the loop.