CODEWITHSUNDEEP
printing
Madhurima Mishra
Madhurima Mishra

Reputation: 1083

printf does not print complete string

It always displays "hello world". Why?

#include <stdio.h>

int main(void)
{
    printf("..... world\rhello\n");
    return 0;
}

Upvotes: 1

Views: 563

Answers (5)

yulian
yulian

Reputation: 1627

Using \r you are returning to the beginning of the current line and're overwriting the dots ".....":

printf("..... world\rhello\n");
        ^^^^^        vvvvv
        hello <----- hello

How it works:

..... world
           ^

then returning to the beginning of the current line:

..... world
^

and then printing a word after \r. The result is:

hello world
           ^

Upvotes: 4

user1814023
user1814023

Reputation: 

#include<stdio.h>
#include<conio.h>
int main(void) 

{   
    // You will hear Audible tone 3 times.
    printf("The Audible Bell --->           \a\a\a\n");
    // \b (backspace) Moves the active position to the 
    // previous position on the current line. 
    printf("The Backspace --->              ___ \b\b\b\b\b\b\b\b\b\bTesting\n");
    //\n (new line) Moves the active position to the initial 
    // position of the next line.
    printf("The newline ---> \n\n");
    //\r (carriage return) Moves the active position to the 
    // initial position of the current line.
    printf("The carriage return --->        \rTesting\rThis program is for testing\n");
    // Moves the current position to a tab space position
    printf("The horizontal tab --->         \tTesting\t\n");

    getch();
    return 0;
}

/***************************OUTPUT************************
The Audible Bell --->
The Backspace --->                        Testing__
The newline --->

This program is for testing
The horizontal tab --->                         Testing
***************************OUTPUT************************/

Upvotes: 0

Gemini
Gemini

Reputation: 89

Check it again, it will give out put like

..... world
hello

and what so over you write inside printf() , it will return that as output

Upvotes: 0

Joey
Joey

Reputation: 354854

This is because \r is a carriage return (CR). It returns the caret to the start of the line. Afterwards you write hello there, effectively overwriting the dots.

\n (line feed, LF) on the other hand used to move the caret just one line downwards, which is why teletypewriters had the sequence CR-LF, or carriage return followed by a line feed to position the caret at the start of the next line. Unix did away with this and LF now does this on its own. CR still exists with its old semantics, though.

Upvotes: 10

unwind
unwind

Reputation: 400129

Because the lone \r (carriage return) character is causing your terminal to go back to the beginning of the line, without changing lines. Thus, the characters to the left of the \r are overwritten by "hello".

Upvotes: 2

Related Questions