Getting Terminal Input in C Program

Getting Input in C Program

In C programming scanf() is one of the commonly used function to take input from the user. The scanf() function reads formatted input from the standard input such as keyboards and store it in variables.

Example 1: Integer Input

#include <stdio.h>
int main()
{
    int myInteger;

    printf("Enter integer value: ");
    scanf("%d", &myInteger);

    printf("myInteger = %d \n", myInteger);
    return 0;
}

Output:

Enter integer value: 10
myInteger = 10

• We have declared a variable myInteger to store integer type values.
• We use %d format specifier inside scanf() to take int input from user
• Notice, that we have used &myInteger inside scanf().
• THis is because, by using &myInteger we are accessing the address of myInteger.
• The value entered by the user is stored in that address.

Example 2: Float and Double Input

// Float and Double Input

#include <stdio.h>
int main()
{
    float myFloat;
    double myDouble;

    printf("Enter a float number: ");
    scanf("%f", &myFloat);

    printf("Enter a double number: ");
    scanf("%lf", &myDouble);

    printf("myFloat = %f \n", myFloat);
    printf("myFloat = %lf \n", myDouble);

    return 0;
}

Output:

Enter a float number: 10.1
Enter a double number: 11.2
myFloat = 10.100000
myFloat = 11.200000

• We use %f and %lf format specifier for float and double respectively

Example 3: Character Input

// Character Input

#include <stdio.h>
int main()
{
    char myChar;

    printf("Enter a character: ");
    scanf("%c",&myChar);

    printf("You entered: %c \n", myChar);

    return 0;
}

Output:

Enter a character: a
You entered: a

• When a character is entered by the user in the above program, the character itself is not stored. Instead, an integer value (ASCII value) is stored.
• When we display that value using %c text format, the entered character is displayed.
• If we use %d to display the character, it's ASCII value is printed.