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In this video, we'll learn about some of the c++ stream manipulators.

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C++ streams have many useful member methods that can be used to

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control formatting.

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There are methods that work on input and output streams,

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but formatting output is much more common.

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An important concept to understand is that when we manipulate a stream for formatting,

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sometimes the settings we make will be set for the remainder of the program,

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other times they'll only affect the next object placed on the stream,

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and sometimes their effect is immediate.

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When we go over the individual formatting methods and manipulators,

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I'll show you the effect each one has as well as how long the effect lasts.

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Most of the stream formatters come in two versions,

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a method version and a manipulator version.

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The method version is simply a method call that you use with the stream object.

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For example, cout.width 10.

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I'll explain what this does in a later section. But for now, you can see the syntax.

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It's calling the width method on the cout object.

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There's also a manipulator version, which is designed

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to be used inline as a stream insertion. In this case, set w10.

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As you probably guessed, the manipulator versions are simply overloading the insertion operator

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to make this easy to use.

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To use the manipulators, you must include io manip.

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The code we'll write will focus mainly on manipulator usage,

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but I'll also show you how to use the methods.

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In the next few videos, we'll go over some of the most commonly used stream manipulators.

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Here's a preview.

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We'll first start by looking at formatting Boolean types.

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We've already seen this used in the course in a few places.

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We can use bool alpha and no bool alpha to display Boolean values

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as either the strings true or false or the integers 1 and 0.

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Then we'll look at formatting integer types.

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These manipulators allow us to display integers base 10, base 16 or base 8

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as well as to decide whether we want the base prefix to show

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and in uppercase or lowercase.

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We can also decide if we want positive numbers to show the plus symbol in front of the number.

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Then we'll switch over to floating point numbers.

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Again, we've already seen some of these manipulators used in the course.

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We can use fixed point, we can set the precision,

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we can show the number in scientific notation format,

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and again, we can decide whether we want trailing 0s printed,

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and whether we want the plus symbol displayed.

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Then we'll learn how to output numbers and strings in fields of fixed width.

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And we can see how we can left or right justify them within that field.

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We'll also be able to fill empty space within the field to a specific character.

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Finally, there are several other formatters that can be very useful.

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Endline, we've already seen and used.

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Flush can be used when we want to be sure that we flush out any stream buffers,

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but it doesn't add a new line like endline does.

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The last few we really won't talk about much, but I'm including them here for your reference.

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Skip white space, no skip white space and white space

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are typically used with input streams when

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when you have very specific use cases about dealing with white space.

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Okay. So in the next video, we'll start with the Boolean formatters. I'll see you there.