// The peek function is predefined in iostream. Its
// purpose is to read one character at a time
// from the input buffer, without removing the content
// of the buffer. Your code will look like this:
ch = cin.peek();
// Note the lack of parameters within the parentheses as
// compared to other cin functions like get or ignore.
// After its execution, the only change will be that ch
// now contains the first character from the input buffer.
// Thde buffer itself is unaffected, containing exactly the
// sequence of characters it held before the peek was
// executed. This can be useful for tasks like making input
// based decisions during execution. Peek might be used in
// the following code to handle input appropriately and
// avoid stream error conditions brought about by improper
// assignment of stream inputs.
int num;
char ch, ch1;
ch = cin.peek;
if ('0' <= ch && ch <= '9')
cin >> num;
else cin(ch1);
// In this case, we are unsure of the type of the next input
// in the buffer, so we use peek to test it and read it into
// memory according to the test,
// if ('0' <= ch && ch <= '9')
// which tests to determine if the next character is a digit
// or a character. Aftedr this test, the appropriate cin
// statement is called.