Format specifiers

C and C++ have format specifiers for formatted input and output. The introductory set used in this series is:

Today, we will use these specifiers to print values.

1. printf("%d", 3); prints the decimal integer 3.
2. printf("%lf", 3.14); prints the floating-point value 3.14 using floating-point formatting.
3. printf("%c", 'A'); prints the single character A.
4. printf("%s", "Hello"); prints the string Hello.

Characters and strings need quotation marks: single quotes for a character such as 'A', and double quotes for a string such as "Hello". Numeric literals do not need quotation marks.

Editorial note: for printf, floating-point arguments are passed as double, and %f is the usual choice. For scanf, %f reads into a float and %lf reads into a double; this distinction matters.

The next lesson will cover input.

Source examples

Print a single character:

// Print the character A

#include <stdio.h> 

int main()
{
    printf("%c",'A');	
    return 0;
}

Print a string:

// Print Hello World!

#include <stdio.h>

int main()
{
    printf("%s","Hello World!");
    return 0;
}

Print an integer:

// Print 3

#include <stdio.h> 

int main()
{
    printf("%d",3);
    return 0;
}

Print a floating-point number:

// Print 3.141592

#include <stdio.h> 

int main()
{
    printf("%lf",3.141592);
    return 0;
}