The Javascript bitwise-and assignment operator (=) Sets the result of a bitwise AND operation on the value of a variable and an expression value. Variables and expressions are treated as 32-bit binary values, and the general expressions are all decimal integers, which need to be converted to the corresponding binary, and then 0 forward to complement 32 bits.
Copy Code code as follows:
Resul
Constructor, destructor, and value assignment operator
Almost all classes have one or more constructors, one destructor, and one value assignment operator. This is not surprising, because they provide some of the most basic functions. The constructor controls the basic operations performed when an object is generated a
Note: classes that contain dynamically assigned members should provide copy constructors and overload the "=" value assignment operator.
The following examples will be used:
Class cexample {public: cexample () {pbuffer = NULL; nsize = 0 ;}~ Cexample () {Delete pbuffer;} void Init (int n) {pbuffer = new char [N]; nsize = N;} PRIVATE: char * pbuffer; // The class object contains a pointer pointing to the dyna
The Quick start tells you how to use arithmetic operators to create new values. For example, the following statement uses the operator + to create a value that is 42 larger than the variable answer, and the new value is written to the console:
Console.WriteLine (answer + 42);
I've also talked about how to use assignment statements to change the value of a variable. The following statement uses the
For assignments of non-intrinsic class objects, there is a default assignment operator overload function.As in the following code, C2=C1 calls the default assignment operator overload function of Class A, which implements the C2.real=c1.real; C2.image=c1.image;classa{Private: intReal; intimage; Public: A (intRint
C ++-copy constructor, copy-assignment operator, destructor, assignmentoperator
For a class, copy constructor, copy-assignment operator, move constructor, move-assignment operator, and destructor are collectively referred to as co
1. What should the overloaded assignment operation function in C + + return? The class overload assignment operator is generally present as a member function, what type should the function return? Refer to the built-in type assignment operations, such asint x, y, Z;x=y=z=15;The a
;
In this case, you need to check the return value of the addition operator to determine whether to call the copy constructor or constructor.
(2) define variables before Initialization
String demo3;
Demo3 = demo1 + demo2;
In this case, you need to check the return value of the addition operator to determine whether to call the copy constructor, constructor, or the copy
1 First distinguishes what is assigned and what is initialized.
2 The overload in the program uses the reference Pass, Reason: ① It is well known that parameters passed by value will produce a copy in the function to be passed, without exception. If the object is large, the copy will waste a lot of sweat space. ② In some cases, you may want to record the number of objects. If the compiler uses an assignment opera
I've talked about how to use arithmetic operators to create new values. For example, the following statement uses the operator + to create a value that is 42 larger than the variable answer, and the new value is written to the console:
Console.WriteLine (answer + 42);
I've also talked about how to use assignment statements to change the value of a variable. The following statement uses the
For a class, we refer to copy constructor, copy-assignment operator, move constructor, move-assignment operator, destructor collectively as copy ControlToday we first talk about the copy constructor, copy-assignment operator destr
Turn from: http://www.kuqin.com/language/20120723/323076.html
In the process of reading "effective C + +" This book, I have countless times to send a sigh, this his mother wrote too good, a sentence on the nail, directly to the point. So I decided to write 5 blogs about the content of this book, and I think it is worth remembering whether you understand these terms or not. The following index corresponds to the chapters in the book.
11: If memory is dynamically configured within class, declare a
First, overload operator= return typeThe following example shows that operator= is similar.For: Ostream operator Explain the points:1. The first parameter is a reference to the Ostream object on which output is generated and ostream is non-const, because writing to the stream alters the state of the stream; The parameter is a reference because the Ostream object
In C ++, the default Return Value Type of the value assignment operator is typename. For example:Int I;I = 3;In fact, I = 3 returns a reference to I, so that I = 3 can be used for continuous operations, suchIf (I = strlen (STR )){... I...}The IF Condition Statement in the above Code not only makes a judgment but also assigns a value to I. It can also be used for Tandem assignment.X = y = z = 3;In fact, this
In the course of reading Objective C ++, I have been sighing for countless times. This is a good fucking write. Therefore, I decided to write the content of this book into five blogs based on my own understanding. I think whether or not you understand these terms is worth writing down. The following indexes correspond to the chapters in the book.
11: if the class is dynamically configured with memory, declare a copy constructor and an assignment
clause 11: Handling "self-assignment" in * * Key content **operator=
"Self-assignment" occurs when an object is assigned to itself:Class widget{...}Widget W;...w=w;//Assign to yourselfa[i]=a[j];//potential self assignment, if I and J have the same value, this is a self assignment
Let's look at the following class that represents a String object:
// A simple string class
Code
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->
Class
String
{
Public
:
String
(
Const
Char
*
Value );
~
String
();...
//
No copy constructor and operator =
Private
:
Char
*
Data;};
String
::
String
(
Const
Char
*
Value){
difference between a copy constructor and an assignment constructor (operator=)
For the copy constructor and the definition of the assignment constructor, I'm not going to nag, or give a simple example, more intuitive.
Class CStr{
Public
CStr (); Default constructor
CSTR (const char* psz); A generalized copy constructor, but some people disagree with my opinion
Recently, in the past, I have seen the article of previous predecessors, for the continuous assignment ( var a={n:1}; A.x=a={n:2}) This knowledge point, at the beginning is not clear, but eventually convinced themselves, to talk about their own experience. The following code can be answered correctly to ignore this article.1 var a={n:1}; 2 var b=A; 3 a.x = a = {N:2}; 4 // ? 5 Console.log (b.x); // ?The correct answer is:a.x= undefined;b.x= {N:2};Wond
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