Зміст курсу
C Basics
C Basics
Printf
Indeed, printf()
is not a standalone function — it's a part of a broader family of functions. This family includes sprintf()
, vprintf()
, vsprintf()
, and vfprintf()
. However, for the purposes of our introductory course, we'll focus solely on printf()
.
Take a look at a typical usage of the printf()
function:
Main
#include <stdio.h> int main() { int iVariable = 832; // declaring and initialization int type variable printf("iVariable = %d \n", iVariable) ; // ??? return 0; }
The output can be broken down into two main parts:
- The format string;
- The data to be displayed.
The data to be displayed is straightforward — it's just the variable we're working with. But let's delve deeper into the format string.
Format String
C language doesn't inherently possess Input/Output (I/O) capabilities. The role of the printf()
function is to take your variable's value, convert its content into characters, and then replace the "%d"
with them.
Format Specifiers
The %d
in our format string is what's called a format specifier.
Format specifiers indicate the type of data that should be displayed within the format string, serving as a heads-up of sorts. In our scenario, the specifier alerts the function to expect integer data. Throughout this course, we'll touch on a few of these specifiers, such as:
%d
– for integers;%f
– for floating-point numbers;%c
- for single characters.
Note
The application of various format specifiers will hinge on your experience with C programming.
This concept aligns with the example we reviewed in the previous lesson:
Main
#include <stdio.h> int main() { int iVariable = 832; // variable of int type float fVariable = 54.984; // variable of float type char cVariable = '#'; // variable of char type printf("iVariable = %d \n", iVariable); // using %d for integer printf("fvariable = %f \n", fVariable); // using %f for float printf("cVariable = %c \n", cVariable); // using %c for single character }
Note
Remember,
"\n"
is a control character that moves subsequent content to a new line.
One of the great things about the printf()
function is its ability to print multiple variables simultaneously!
main
#include <stdio.h> int main() { int iVariable = 832; float fVariable = 54.984; char cVariable = '#'; printf(" iVariable = %d \n fvariable = %f \n cVariable = %c \n", iVariable, fVariable, cVariable); return 0; }
Here, the format specifiers and the variables are paired in sequence:
However, if you mismatch the specifier, your program will not display the data correctly:
Main
# include <stdio.h> int main() { int iVariable = 1234; printf("%f", iVariable); // %f - a floating point number for floats return 0; }
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