How does printf() in C output Hello world—character by character or all at once?

Hi guys, I'm just wondering about function printf in C programming.lets assume I want to read "Hello world" , so I did in my compiler printf("Hello world") , what's confusing me, the PC will go to the address where the "Hello world" found, and he will print it, So confusing me, how's printing it, one by one? or just print it as complete value? I mean does he use sequential printing char by char on my screen? or doing in parallel read/printf for every char in "Hello world" so it's shown up on my screen as complete intact value?! I guess the PC print char by char and it takes time to print char from char no?thanks alot!!!

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Ryan,In the C implementations that I'm aware of, printf "prints" one character at a time. As Mike pointed out, if the display device has a frame buffer, then it could save the characters and send the data to the display all at once but that would be done in hardware not in C.

Guys, what does it mean "prints" one character at a time, you mean it reads/prints one character sequentially?! or in parallel? what do you mean "at a time" .. you mean it reads one character .. then print it, and afterwards going to the other character and prints it ..etc?


and can the PC print in parallel?

I mean, by the hardware of PC , we possible to print/read chars in parallel or sequential?

Ryan,You have it right. printf reads one character, prints it, then reads the next etc.Now when we say that printf has printed the character, what we mean is that the character is sent to where it can be seen. Now after that, the C program has nothing more to do with it but it's possible that there is a hardware buffer that causes all (or a certain number) the characters to appear at once depending on what you are printing to.These days most PCs are so fast that you can't tell the difference between the data coming out one at a time or in parallel.