C Programming Quiz & Flashcards: Field Width & Specifiers

What does the field-width specifier in C refer to?

In the statement printf("Area = %4d", area);, what does '4' represent?

If the value of the variable 'area' is 7 and printf("Result = %3d", area); is used, how will it be displayed?

Why are two blank spaces added before '25' when using printf("Area = %4d", area); with area as 25?

If printf("Length = %6d", length); is executed with length as 123, how many spaces will precede '123' in the output?

What does the last row of the table indicate about how C handles field width for integer values?

What information is required to format floating point numbers according to the text?

What should be included in the total field width when formatting floating point numbers smaller than zero?

What does % m.nf represent in the format specifier for a floating point value?

What does adding a zero before a decimal point signify in formatting floating point numbers?

Field-width Specifier in C

A field-width specifier in C controls the minimum number of character spaces allocated for output data.
It ensures values are aligned in a specific width, improving readability in display output.

Example of Field-width Specification

In printf("Area = %4d", area);, the '4' indicates that the output should occupy at least 4 character spaces.
If the actual number has fewer digits, spaces will be added before the number to reach the specified width.

Output Behavior

Using printf("Result = %3d", area); with area as 7 will display as Result = 7, with one space before '7' to meet the width requirement of 3.
For printf("Area = %4d", area); with area set to 25, the output will show Area = 25, including two leading spaces to match the width of 4.

Space Calculation in Output

Executing printf("Length = %6d", length); with length as 123 results in Length = 123, with three spaces preceding '123' for a total width of 6.

Handling Field Width in C

The last row of the table generally illustrates that C pads integer outputs with spaces on the left when they fall short of the specified field width.

Formatting Floating Point Numbers

To format floating point numbers, one needs to specify both the total field width and the number of digits after the decimal point.
The formatting specifier for floating points follows the pattern %m.nf, where 'm' is the total width and 'n' represents the number of digits after the decimal.

Total Field Width Considerations

When formatting floating point numbers that are negative, the '-' sign is included in the total field width calculation.

Significance of Adding a Zero

Adding a zero before a decimal point in a floating point format specifier (%0m.nf) indicates that leading zeros should be used to fill in for the specified width, instead of spaces.

This quiz covers the concept of field-width specifier in C programming, particularly focusing on formatting integers for display. Learn how to specify the number of columns to be used when printing integer values on the screen using the %d format specifier in printf statements.