Merge pull request #5642 from MicrosoftDocs/main

8/12/2024 AM Publish

Author: Albertyang0

docs/c-runtime-library/reference/not-eq.md

@@ -1,17 +1,16 @@
 ---
 description: "Learn more about: not_eq"
 title: "not_eq"
-ms.date: "11/04/2016"
+ms.date: 08/09/2024
 api_location: ["msvcrt.dll", "msvcr80.dll", "msvcr90.dll", "msvcr100.dll", "msvcr100_clr0400.dll", "msvcr110.dll", "msvcr110_clr0400.dll", "msvcr120.dll", "msvcr120_clr0400.dll", "ucrtbase.dll"]
 api_type: ["DLLExport"]
 topic_type: ["apiref"]
 f1_keywords: ["ISO646/not_eq", "not_eq", "std::not_eq", "std.not_eq"]
 helpviewer_keywords: ["not_eq function"]
-ms.assetid: d87ad299-8b50-4393-a57f-06f70e1f23fb
 ---
 # `not_eq`
 
-An alternative to the **`!=`** operator.
+An alternative spelling for the **`!=`** operator.
 
 ## Syntax
 
@@ -21,34 +20,40 @@ An alternative to the **`!=`** operator.
 
 ## Remarks
 
-The macro yields the operator **`!=`**.
+C++:
+- **`not_eq`** can be used as alternative to **`!=`**. The [`/permissive-`](../../build/reference/permissive-standards-conformance.md) or [`/Za`](../../build/reference/za-ze-disable-language-extensions.md) compiler option is required.
+- Including `<iso646.h>` or `<ciso646>` is deprecated. You can use the alternative spelling without including any header files.
+- There's no alternative spelling for **`==`**.
+
+C:
+- **`not_eq`** is an alternative spelling for **`!=`**. It is provided as a macro in `<iso646.h>`, which you must `#include`.
+- There's no alternative spelling for **`==`**.
 
 ## Example
 
 ```cpp
-// iso646_not_eq.cpp
 // compile with: /EHsc
 #include <iostream>
 #include <iso646.h>
 
 int main( )
 {
-   using namespace std;
-   int a = 0, b = 1;
-
-   if (a != b)
-      cout << "a is not equal to b" << endl;
-
-   if (a not_eq b)
-      cout << "a is not equal to b" << endl;
+   int x = 1, y = 2;
+    
+    // not_eq is available in C++ and C
+    // This example is for C++, so no header file is needed to use not_eq
+    // When compiling for C, #include <iso646.h> to use not_eq
+    if (x not_eq y)
+    {
+        std::cout << "Not equal\n";
+    }
 }
 ```
 
 ```Output
-a is not equal to b
-a is not equal to b
+Not equal
 ```
 
 ## Requirements
 
-**Header:** \<iso646.h>
+**Header:** `<iso646.h>` is necessary if you are compiling for C.

docs/cpp/equality-operators-equal-equal-and-exclpt-equal.md

@@ -1,10 +1,9 @@
 ---
 title: "Equality operators: == and !="
 description: "The C++ standard language equal-to and not-equal-to operator syntax and use."
-ms.date: 07/23/2020
-f1_keywords: ["!=", "==", "not_eq_cpp"]
-helpviewer_keywords: ["!= operator", "equality operator", "not equal to comparison operator", "equality operator [C++], syntax", "== operator", "not_eq operator", "equal to operator"]
-ms.assetid: ba4e9659-2392-4fb4-be5a-910a2a6df45a
+ms.date: 08/09/2024
+f1_keywords: ["!=", "=="]
+helpviewer_keywords: ["!= operator", "equality operator", "not equal to operator", "equality operator [C++], syntax", "== operator", "equal to operator"]
 ---
 # Equality operators: `==` and `!=`
 
@@ -15,38 +14,41 @@ ms.assetid: ba4e9659-2392-4fb4-be5a-910a2a6df45a
 
 ## Remarks
 
-The binary equality operators compare their operands for strict equality or inequality.
+The equal-to operator (**`==`**) returns **`true`** if both operands have the same value; otherwise **`false`**.\
+The not-equal-to operator (**`!=`**) returns **`true`** if the operands don't have the same value; otherwise **`false`**.
 
-The equality operators, equal to (**`==`**) and not equal to (**`!=`**), have lower precedence than the relational operators, but they behave similarly. The result type for these operators is **`bool`**.
-
-The equal-to operator (**`==`**) returns **`true`** if both operands have the same value; otherwise, it returns **`false`**. The not-equal-to operator (**`!=`**) returns **`true`** if the operands don't have the same value; otherwise, it returns **`false`**.
-
-## Operator keyword for !=
-
-C++ specifies **`not_eq`** as an alternative spelling for **`!=`**. (There's no alternative spelling for **`==`**.) In C, the alternative spelling is provided as a macro in the \<iso646.h> header. In C++, the alternative spelling is a keyword; use of \<iso646.h> or the C++ equivalent \<ciso646> is deprecated. In Microsoft C++, the [`/permissive-`](../build/reference/permissive-standards-conformance.md) or [`/Za`](../build/reference/za-ze-disable-language-extensions.md) compiler option is required to enable the alternative spelling.
+In C and C++, **`not_eq`** can be used as alternative to **`!=`**. For more information, see [`not-eq`](../c-runtime-library/reference/not-eq.md).
 
 ## Example
 
 ```cpp
-// expre_Equality_Operators.cpp
-// compile with: /EHsc
 #include <iostream>
 
-using namespace std;
-
-int main() {
-   cout  << boolalpha
-         << "The true expression 3 != 2 yields: "
-         << (3 != 2) << endl
-         << "The false expression 20 == 10 yields: "
-         << (20 == 10) << endl;
+int main()
+{
+    int x = 1, y = 1, z = 2;
+    
+    if (x == y)
+    {
+        std::cout << "Equal\n";
+    }
+    
+    if (x != z)
+    {
+        std::cout << "Not equal\n";
+    }
 }
 ```
 
-Equality operators can compare pointers to members of the same type. In such a comparison, pointer-to-member conversions are performed. Pointers to members can also be compared to a constant expression that evaluates to 0.
+```output
+Equal
+Not equal
+```
 
 ## See also
 
+[`not-eq`](../c-runtime-library/reference/not-eq.md)\
+[Operator overloading](../cpp/operator-overloading.md)\
 [Expressions with binary operators](../cpp/expressions-with-binary-operators.md)\
 [C++ built-in operators, precedence; and associativity](../cpp/cpp-built-in-operators-precedence-and-associativity.md)\
 [C relational and equality operators](../c-language/c-relational-and-equality-operators.md)