Why is iomanip used in c

We have taken just one function for our understanding. We have taken a number where we are setting the precision. The iomanip library enables to change the precision. Initially, the precision is default and then we change it to 3 using the setprecision function. This changes the precision value and the decimal number will not take only the first 3 decimal places. The output will be manipulated and the output will be displayed accordingly. This is because of the iomanip library. Explanation: The above program helps us understand 5 functions of iomanip library.

We have imported the library iomanip which has manipulation functions present. We have used 5 functions. The first function is setprecision which helps in setting precision of the number defined.

This example shows how to use quoted with the default delimiter and escape character using narrow strings. Wide strings are equally supported. The manipulator returns an object that, when extracted from or inserted into the stream str , calls str.

See setw for an example of using resetiosflags. Here, mask is determined as follows:. See setw for an example of using setbase. Ch The character that will be used to fill spaces in a right-justified display. The template manipulator returns an object that, when extracted from or inserted into the stream str , calls str.

Viewed 22k times. Improve this question. This may be the first time I've seen someone who understands how to use iostream formatters and not how to do the equivalent thing with printf Yeah, I run into the same things all the time.

Add a comment. Active Oldest Votes. Improve this answer. Note that placing a - in front of the padding number will cause the output to align to the left. Related Answer — user No, since the stream used in C doesn't maintain state the way the stream object does.

You need to specify with e. I need the equivalent formatting of 'setw 2 ' Dealing with Spacing Issues using iomanip A principle aspect of nicely formatted output is that the spacing looks right.

There aren't columns of text that are too long or too short, and everything is appropriately aligned. This section deals with ways of spacing output correctly. Setting the field width with setw The std::setw function allows you to set the minimum width of the next output via the insertion operator. There is no effect if the output is longer than the width--note that the output won't be truncated.

The only strange thing about setw is that its return value must be inserted into the stream.