Skip to content

typo in code example #3323

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
Kristine Toliver (ktoliver) merged 3 commits into from
Aug 30, 2021
Merged

typo in code example #3323

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
c28b98f
typo in code example
BugCheck141 Aug 25, 2021
555a10e
Update output-file-stream-member-functions.md
TylerMSFT Aug 25, 2021
477b4c6
PR review edit, date
ktoliver Aug 30, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
33 changes: 16 additions & 17 deletions docs/standard-library/output-file-stream-member-functions.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,26 +1,25 @@
---
description: "Learn more about: Output File Stream Member Functions"
title: "Output File Stream Member Functions"
ms.date: "11/04/2016"
ms.date: "08/25/2021"
helpviewer_keywords: ["output streams [C++], member functions"]
ms.assetid: 38aaf710-8035-4a34-a0c4-123a5327f28a
---
# Output File Stream Member Functions

Output stream member functions have three types: those that are equivalent to manipulators, those that perform unformatted write operations, and those that otherwise modify the stream state and have no equivalent manipulator or insertion operator. For sequential, formatted output, you might use only insertion operators and manipulators. For random-access binary disk output, you use other member functions, with or without insertion operators.

## The open Function for Output Streams

To use an output file stream ([ofstream](../standard-library/basic-ofstream-class.md)), you must associate that stream with a specific disk file in the constructor or the `open` function. If you use the `open` function, you can reuse the same stream object with a series of files. In either case, the arguments describing the file are the same.
To use an output file stream ([`ofstream`](../standard-library/basic-ofstream-class.md)), you must associate that stream with a specific disk file in the constructor or the `open` function. If you use the `open` function, you can reuse the same stream object with a series of files. In either case, the arguments describing the file are the same.

When you open the file associated with an output stream, you generally specify an `open_mode` flag. You can combine these flags, which are defined as enumerators in the `ios` class, with the bitwise OR ( | ) operator. See [ios_base::openmode](../standard-library/ios-base-class.md#openmode) for a list of the enumerators.
When you open the file associated with an output stream, you generally specify an `open_mode` flag. You can combine these flags, which are defined as enumerators in the `ios` class, with the bitwise OR ( `|` ) operator. See [`ios_base::openmode`](../standard-library/ios-base-class.md#openmode) for a list of the enumerators.

Three common output stream situations involve mode options:

- Creating a file. If the file already exists, the old version is deleted.

```cpp
ostream ofile("FILENAME");
ofstream ofile("FILENAME");
// Default is ios::out

ofstream ofile("FILENAME", ios::out);
Expand All @@ -46,9 +45,9 @@ Three common output stream situations involve mode options:
// When ofile goes out of scope it is destroyed.
```

## The put
## The `put` function

The **put** function writes one character to the output stream. The following two statements are the same by default, but the second is affected by the stream's format arguments:
The `put` function writes one character to the output stream. The following two statements are the same by default, but the second is affected by the stream's format arguments:

```cpp
cout.put('A');
Expand All @@ -57,7 +56,7 @@ cout.put('A');
cout <<'A'; // Format arguments 'width' and 'fill' apply
```

## The write
## The `write` function

The `write` function writes a block of memory to an output file stream. The length argument specifies the number of bytes written. This example creates an output file stream and writes the binary value of the `Date` structure to it:

Expand All @@ -80,7 +79,7 @@ int main( )
}
```

The `write` function does not stop when it reaches a null character, so the complete class structure is written. The function takes two arguments: a **`char`** pointer and a count of characters to write. Note the required cast to **`char`**<strong>\*</strong> before the address of the structure object.
The `write` function does not stop when it reaches a null character, so the complete class structure is written. The function takes two arguments: a **`char`** pointer and a count of characters to write. Note the required cast to **`char *`** before the address of the structure object.

## The seekp and tellp Functions

Expand All @@ -98,12 +97,12 @@ Use these member functions to test for errors while writing to a stream:

|Function|Return value|
|--------------|------------------|
|[bad](basic-ios-class.md#bad)|Returns **`true`** if there is an unrecoverable error.|
|[fail](basic-ios-class.md#fail)|Returns **`true`** if there is an unrecoverable error or an "expected" condition, such as a conversion error, or if the file is not found. Processing can often resume after a call to `clear` with a zero argument.|
|[good](basic-ios-class.md#good)|Returns **`true`** if there is no error condition (unrecoverable or otherwise) and the end-of-file flag is not set.|
|[eof](basic-ios-class.md#eof)|Returns **`true`** on the end-of-file condition.|
|[clear](basic-ios-class.md#clear)|Sets the internal error state. If called with the default arguments, it clears all error bits.|
|[rdstate](basic-ios-class.md#rdstate|Returns the current error state.|
|[`bad`](basic-ios-class.md#bad)|Returns **`true`** if there is an unrecoverable error.|
|[`fail`](basic-ios-class.md#fail)|Returns **`true`** if there is an unrecoverable error or an "expected" condition, such as a conversion error, or if the file is not found. Processing can often resume after a call to `clear` with a zero argument.|
|[`good`](basic-ios-class.md#good)|Returns **`true`** if there is no error condition (unrecoverable or otherwise) and the end-of-file flag is not set.|
|[`eof`](basic-ios-class.md#eof)|Returns **`true`** on the end-of-file condition.|
|[`clear`](basic-ios-class.md#clear)|Sets the internal error state. If called with the default arguments, it clears all error bits.|
|[`rdstate`](basic-ios-class.md#rdstate|Returns the current error state.|

The **!** operator is overloaded to perform the same function as the `fail` function. Thus the expression:

Expand All @@ -117,7 +116,7 @@ is equivalent to:
if(cout.fail())...
```

The **void\*()** operator is overloaded to be the opposite of the **!** operator; thus the expression:
The **`void*()`** operator is overloaded to be the opposite of the **`!`** operator; thus the expression:

```cpp
if(cout)...
Expand All @@ -129,7 +128,7 @@ is equal to:
if(!cout.fail())...
```

The **void\*()** operator is not equivalent to `good` because it does not test for the end of file.
The **`void*()`** operator is not equivalent to `good` because it does not test for the end of file.

## See also

Expand Down