Topic 3 - Formatted Input/Output

Question 1

What is a conversion specification?

Answer 1

A placeholder.

Question 2

What is %d used for

Answer 2

int values as a conversion specifier

Question 3

What is %f used for

Answer 3

float values as a conversion specifier

Question 4

Too many conversion specifications _____ produce meaningless output.

Answer 4

will

Question 5

Too few conversion specifications _____ produce meaningless output

Answer 5

might

Question 6

Incorrect specification ____ produce meaningless output

Answer 6

will

Question 7

In the conversion specification form: %m.pX (or %-m.pX) - what is m?

Answer 7

minimum field width - specifies the minimum number of characters to print

Question 8

What happens when the value to be printed requires fewer than m characters?

Answer 8

It will be right-justified within the field and space characters will be inserted to its left

Question 9

What does putting a minis sign in front of m do?

Answer 9

causes left justification in the event that the value to be printed requires fewer than m characters. Space characters are then inserted to the right of the value instead.

Question 10

What happens if the value to be printed requires more than m characters?

Answer 10

the field with automatically expands to the necessary size.

Question 11

The main of p in %m.pX depends on what.

Answer 11

The choice of X, the conversion specifier.

Question 12

What does “p” indicate for %d specifier?

Answer 12

The minimum number of digits to be displayed - extra zeros are added to the beginning of the number, if necessary

Question 13

If p is omitted with %d, what happens.

Answer 13

P is assumed to be 1.

Question 14

What does p indicate for %f?

%e?

Answer 14

%f - fixed decimal format - p indicates the number of digits after the decimal point
%e - exponential format - p as the same meaning as for the f specified

Question 15

What does p indicate for %g?

Answer 15

%g - either exponential format or fixed decimal format, depending on the number to b printed - e format is selected in case of too small numbers

Question 16

Does the %g conversion show trailing zeros?

Answer 16

No

Question 17

If the number has no digits after the decimal point, does g display the decimal point?

Answer 17

No.

Question 18

What does scanf do when it arrives at the final new-line?

Answer 18

It “peeks” at the final new-line without reading it.

Question 19

How does scanf work when asked to read an integer?

Answer 19

• first looks for a plus / minus sign (optional), followed by
• digits
• it then reads digits until it reaches a non-digit

Question 20

How does scanf work when asked to read a floating-point number?

Answer 20

• looks for plus or minus sign (optional)
• followed by digits (possibly containing a decimal point)
• it then reads digits until it reaches a non-digit

Question 21

What happens when scanf encounters a character that can’t be part of the current item?

Answer 21

The character is “put back” to be read again during the scanning of the next input item

Question 22

Scanf’s format string capabilities:
If the format string is “%d/%d” and the input is •5/•96¤
Does it fail or succeed?

Answer 22

The / from the input matches the / in the format string in the scanf’s arguments so it succeeds.

Question 23

If the format string is “%d/%d” and the input is •5•/•96¤

Does it fail or succeed/

Answer 23

the “ / “ has a space character before the “/” that does not match the format string

Question 24

If the format string is
“%d / %d” and the input is”
If the format string is “%d/%d” and the input is
•5/•96¤

5/96¤

•5•••••/•••••••96¤

5¤
/¤
96¤

Answer 24

• succeed
• succeed
• succeed
• succeed