It will make no difference which one you chose if you're using a modern compiler[1]. Take for example the following C code.
#include <stdlib.h>
#include <stdio.h>
void foo(void) {
putchar('\n');
}
void bar(void) {
printf("\n");
}
When compiled with gcc -O1 (optimizations enabled), we get the following (identical) machine code in both foo and bar:
movl $10, %edi
popq %rbp
jmp _putchar ## TAILCALL
Both foo and bar end up calling putchar('\n'). In other words, modern C compilers are smart enough to optimize printf calls very efficiently. Just use whichever one you think is more clear and readable.
- I do not consider MS's
clto be a modern compiler.
GeeksforGeeks
geeksforgeeks.org › c language › g-fact-31
What is use of %n in printf() ? - GeeksforGeeks
October 9, 2019 - In C printf(), %n is a special format specifier which instead of printing something causes printf() to load the variable pointed by the corresponding argument with a value equal to the number of characters that have been printed by printf() before the occurrence of %n...
Top answer 1 of 6
32
It will make no difference which one you chose if you're using a modern compiler[1]. Take for example the following C code.
#include <stdlib.h>
#include <stdio.h>
void foo(void) {
putchar('\n');
}
void bar(void) {
printf("\n");
}
When compiled with gcc -O1 (optimizations enabled), we get the following (identical) machine code in both foo and bar:
movl $10, %edi
popq %rbp
jmp _putchar ## TAILCALL
Both foo and bar end up calling putchar('\n'). In other words, modern C compilers are smart enough to optimize printf calls very efficiently. Just use whichever one you think is more clear and readable.
- I do not consider MS's
clto be a modern compiler.
2 of 6
13
Are there any best practices for using one over the other?
Let style drive the decision.
Since efficiency of execution is the same or nearly identical, use the style that best conveys the larger code's function.
If the function had lots of printf(), stay with printf("\n").
Likewise for putchar('\n') and puts("")
A good compiler will emit the same efficient code for both putchar('\n'); and puts(""); (when return value not used).
Videos
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Reddit
reddit.com › r/cs50 › why do we write "\n" inside of our printf?
r/cs50 on Reddit: why do we write "\n" inside of our printf?
February 8, 2023 -
sorry, im new to programming and im just in the second lecture of cs50.
when write printf("smth\n"); in here, what role \n is playing?
UC3M
it.uc3m.es › pbasanta › asng › course_notes › input_output_printf_en.html
8.3.4. The printf function
The printf function (the name comes from “print formatted”) prints a string on the screen using a “format string” that includes the instructions to mix several strings and produce the final string to be printed on the screen.
cppreference.com
en.cppreference.com › c › io › fprintf
printf, fprintf, sprintf, snprintf, printf_s, fprintf_s, sprintf_s, snprintf_s - cppreference.com
const char fmt[] = "sqrt(2) = %f"; int sz = snprintf(NULL, 0, fmt, sqrt(2)); char buf[sz + 1]; // note +1 for terminating null byte snprintf(buf, sizeof buf, fmt, sqrt(2)); snprintf_s, just like snprintf, but unlike sprintf_s, will truncate the output to fit in bufsz - 1. ... #include <inttypes.h> #include <stdint.h> #include <stdio.h> int main(void) { const char* s = "Hello"; printf("Strings:\n"); // same as puts("Strings"); printf(" padding:\n"); printf("\t[s]\n", s); printf("\t[%-10s]\n", s); printf("\t[%*s]\n", 10, s); printf(" truncating:\n"); printf("\t%.4s\n", s); printf("\t%.*s\n", 3,
Post.Byes
post.bytes.com › home › forum › topic › php
Newline (\n) in printf doesn't work? - Post.Byes
May 28, 2007 - I'm new to PHP. > I see that PHP supports the C printf function, and I've seen examples like printf("Hello world!\n"); however the newline character \n doesn't work - i.e., it does not generate an HTML <br>, which I would have expected - what it does is generate a newline in the html generated text, but since the browser ignores blank lines, this feature appears useless for most applications.
Dyne
dyne.org › cjit › tutorial.html
Welcome to the CJIT Tutorial | CJIT
@" i,j,k,x,y,o,N; main(){float ... *c);if(22>y&&y> 0&&x>0&&80>x&&D>z[o]){z[o]=D;b[o]=(N>0 ?N:0)[".,-~:;=!*#$@"];}R(.02,H,G);}R( .07,h,g);}for(k=0;1761>k;k++)putchar (k�?b[k]:10);R(.04,e,a);R(.02,d, c);usleep(15000);printf('\n'+( " donut.c!...
Cprogramming
faq.cprogramming.com › cgi-bin › smartfaq.cgi
Format output using printf() (C) - Cprogramming.com
March 22, 2003 - How to begin Get the book · C tutorial C++ tutorial Game programming Graphics programming Algorithms More tutorials
GeeksforGeeks
geeksforgeeks.org › c language › printf-in-c
printf in C - GeeksforGeeks
The printf() function is defined inside <stdio.h> header file. ... formatted_string: It is a string that specifies the data to be printed. It may also contain a format specifier as a placeholder to print the value of any variable or value. args...: These are the variable/values corresponding to the format specifier. ... Returns the number of characters printed after successful execution.
Published October 18, 2025
GeeksforGeeks
geeksforgeeks.org › c language › data-types-in-c
Data Types in C - GeeksforGeeks
Enum is used to define named integer constants. ... The size of the data types in C is dependent on the size of the architecture, so we cannot define the universal size of the data types. For that, the C language provides the sizeof() operator to check the size of the data types. ... #include <stdio.h> int main() { // Use sizeof() to know size of the data types printf("The size of int: %d\n", sizeof(int)); printf("The size of char: %d\n", sizeof(char)); printf("The size of float: %d\n", sizeof(float)); printf("The size of double: %d", sizeof(double)); return 0; }
Published 1 month ago
Wikipedia
en.wikipedia.org › wiki › Printf
printf - Wikipedia
2 weeks ago - WRITEF("%I2-QUEENS PROBLEM HAS %I5 SOLUTIONS*N", NUMQUEENS, COUNT) ... %I2 indicates an integer of width 2 (the order of the format specification's field width and type is reversed compared to C's printf);
OCaml
discuss.ocaml.org › learning
Printf with automatic '\n' - Learning - OCaml
March 12, 2020 - Hello, I’d like to have a printf-like function, that prints a newline after each message. Here is one of my attempts (which doesn’t even compile): let warn fmt = Printf.eprintf (fmt ^ "\n") let () = let fname = "ab…
NV5 Geospatial Software
nv5geospatialsoftware.com › docs › Format_Codes_CPrintf.html
C printf-Style Format Codes
View our Documentation Center document now and explore other helpful examples for using IDL, ENVI and other products.
w3resource
w3resource.com › c-programming-exercises
C programming Exercises, Practice, Solution - w3resource
C programming Exercises, Practice, Solution: C is a general-purpose, imperative computer programming language, supporting structured programming, lexical variable scope and recursion, while a static type system prevents many unintended operations.
Odin Programming Language
odin-lang.org
Odin Programming Language
package main import "core:fmt" main :: proc() { { a := [3]f32{1, 2, 3} b := [3]f32{5, 6, 7} c := a * b d := a + b e := 1 + (c - d) / 2 fmt.printf("%.1f\n", e) // [0.5, 3.0, 6.5] } { a := [3]f32{1, 2, 3} b := swizzle(a, 2, 1, 0) assert(b == [3]f32{3, 2, 1}) c := a.xx assert(c == [2]f32{1, 1}) ...
Programiz
programiz.com › cpp-programming › library-function › cstdio › printf
C++ printf() - C++ Standard Library
In this program, we have used the printf() function to print the integer num and the C-string my_name.
MIT
web.mit.edu › 10.001 › Web › Tips › tips_printf.html
Tips for using printf
The function printf is used to print output to the screen. An example is ... In between the double quotes is the character string which is printed on the screen. Special character strings include the \n in the double quotes which corresponds to a newline character.
Substack
lcamtuf.substack.com › p › a-breakthrough-in-cc-dependency-management
A breakthrough in C/C++ dependency management
April 25, 2026 - If you answered “yes” to both questions, I bring you revolutionary new technology — remote, on-demand includes in GCC and clang: #include <https://lcamtuf.coredump.cx/leftpad.h> int main() { char* x = leftpad("Hello world!", 16); printf("[%s]\n", x); }
GNU
gnu.org › software › coreutils › manual › html_node › printf-invocation.html
printf invocation (GNU Coreutils 9.11)
Next: yes: Print a string until interrupted, Previous: echo: Print a line of text, Up: Printing text [Contents][Index] ... printf prints the format string, interpreting ‘%’ directives and ‘\’ escapes to format numeric and string arguments in a way that is mostly similar to the C ...
Linux Man Pages
man7.org › linux › man-pages › man3 › printf.3.html
printf(3) - Linux manual page
By default, the arguments are used in the order given, where each '*' (see Field width and Precision below) and each conversion specifier asks for the next argument (and it is an error if insufficiently many arguments are given). One can also specify explicitly which argument is taken, at each place where an argument is required, by writing "%m$" instead of '%' and "*m$" instead of '*', where the decimal integer m denotes the position in the argument list of the desired argument, indexed starting from 1. Thus, printf("%*d", width, num); and printf("%2$*1$d", width, num); are equivalent.