Why does my cout output not appear immediately?

Question

it does not print the string put in the loop. The program was written with the help of G++, with sys/types.h header file included

for(int i=0;i<9;i++)
{
          


        

Answer 1

You're not flushing your output.

std::cout << "||" << std::flush;

Answer 2

What you're likely seeing here is an effect of the output being buffered. In general the output won't actually be written until std::endl is used.

for(int i=0;i<9;i++)
{
    // Flushes and adds a newline
    cout<< "||" << endl;
    sleep(1);
}

Under the hood std::endl is adding a newline character and then using std::flush to force the output to the console. You can use std::flush directly to get the same effect

for(int i=0;i<9;i++)
{
    cout << "||" << flush;
    sleep(1);
}