C ++ Primer

An example of reading an unknown object

# Include <iostream>

Using namespace STD;

Int main ()

{

Int sum = 0, value;

While (CIN> value)

Sum + = value;

Cout <sum;

}

In this example, the cycle condition is different from the previous carriage return and space conditions. I thought for more than half an hour and finally got the answer.

in many cases, we mistakenly think of the loop end sign (confusing) as a carriage return or space ), however, they only end with one input. In C ++, The istream object is used as the loop condition (key) to test the input stream status. If the test succeeds, the statement is executed. If Ctrl + D or Ctrl + z (File Terminator) is run ), or the input is invalid.