CS 150 Introduction to C++ Programming - Spring 1998 

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Standard Input of Integers (Exercise 7 Chapter 4)

Standard input is extracted cin, the standard input stream using the extraction operator (>>).
When inputting a number, the extraction operator will "search" for the number by skipping over any leading whitespace (blanks and end of lines).
Input stops when an inappropriate character for that number type is found.
Thus >> reads only as many characters from cin as are needed to form a number.
Any characters after the number (including the character that stopped the input) are still available for the next input operation.

If you want to skip over some of the input, you can use the ignore operator. Ignore takes two arguments,

• the first is a number, which is the maximum number of characters to ignore
• the second is the stop character

ignore will either ignore all input characters up to the maximum number or until a stop character is found, whichever comes first.

(see pages 141-142 in the textbook).

	cin >> int1;
	cin.ignore(200,'\n');
	cin >> int1 >> int3;
	cin.ignore(200, '\n');
	cin >> int4;

Choose one when done

Copyright chris wild 1998.
For problems or questions regarding this web contact [Dr. Wild (e-mail:wild@cs.odu.edu].
Last updated: February 10, 1998.