Operators in PHP --- Arithmetic Operators, logical operators, value assignment operators, comparison operators, and operator assignment
1. Arithmetic Operators
Common Arithmetic Operators
Operation Type
Operator
Example
Result
Inverse Operation
-
-$
Returns a negative value of $.
The most basic form of the value assignment operator is "". here, "" is not "equal to", but a value assignment. its function is to assign values to variables simply, for example, $ A10 means to assign 10 to $ A, so that the value of $ A is 10.
What is the php value assignment opera
In this article, let's talk about the assignment operator in the python operator, and hopefully this article will give you some help in learning about Python.
Assignment operators:
The following assumes that the variable A is 10 and the variable B is 20:
= Simple assignment
Simple assignmentIn the C language, operator = does not represent equality, but an assignment operator. This means that the left side of the symbol = is a modifiable variable name, and the right is the value assigned to the variable.The following program statements:i = i+1; Mathematically, the equation is not tenable. As an
mystr operator = (const mystr str)//assignment operator { cout Ⅱ . ParametersIn general, the argument to the overloaded function of the assignment operator is a reference to the const type of the class in which the function is located (as in Example 1 above), and t
What is the PHP assignment operator?
The most basic form of the assignment operator is "=", where the "=" is not "equal to", is the meaning of the assignment, it is the function of the simple point is to assign value to the variable, for example, $a=10, meaning to give 10
Translation: Value assignment operator (: =) (submitted to the MariaDB official Manual), operator mariadb
This article is a translation of the value assignment operator (: =) in the mariadb official manual.
Original article: https://mariadb.com/kb/en/
TheValue assignment operator overload FunctionThe function is similar to that of the built-in value assignment operator. However, you must note that it is the same as the copy constructor and the destructor. Pay attention to the issue of deep copy and shallow copy, if you do not specify the default value
is no longer involved in the operation. So the result is x=2 y=1 (++y = = 2 Not participating in the operation)
int x = 1,y = 1;
if (x++==1 | ++y==1) {
x = 7;
}
System.out.println ("x=" +x+ ", y=" +y);
The result above is x=7,y=2 because | operations, regardless of the left is true false right are involved in the operation, so ++y = = 1 to participate in the operation. At this point the if condition is set to execute x = 7.
int x = 1,y = 1;
if (x++==1
To assign values to different variables, you must use the assign operator "=". Here "=" does not mean "equal to", but "assign value". For example:
A1 = 3;
This statement is used to assign integer 3 to variable a1. Make the value of variable a1 3 at this time. Let's look at the following statement:
A1 = a1 + 1;
As you know, this representation method won't work in mathematics, but as a value assignment state
As we mentioned earlier, when there is no user-defined assignment operator, the compiler defaults to generating a shallow copy
If the pointer not only assigns the value to the point, it is also assigned to the address, which causes the problem
Does this question apply to the reference?
#include
This is not allowed, only the user can create the operator
m
C ++ from scratch (4)
-- Value assignment operator
This article is a continuation of "C ++ from scratch (ii)" and describes the content of expressions left over from "C ++ from scratch (ii, it also paves the way for the use of pointers in the next article. Although the previous article has already explained what the variable is, the most critical things of the variable are not described Due to space limit
The previous section describes the built-in variables in PowerShell, and the details are poked here.This section describes the assignment operators in PowerShell , which assign one or more values to a variable. The assignment operator can perform a numeric operation on a value before assigning it.PowerShell supports the following
point to derived class objects:1 class Base {...}; 2 3 class Public Base {...}; 4 5 void dosomething (const/ RB and *PD might actuallybe67 // The same object2. Handling bad self-assignment can cause you to fall into the trap. If you follow the advice of Item13 and ITEM14, you will use objects to manage resources, and you can be confident that the objects that manage the resources will run well when they are copied. In this case, your
Item 11: Processing assignment to self in operator = (Auto assigned)
By Scott Meyers
Translator: fatalerror99 (itepub's nirvana)
Release: http://blog.csdn.net/fatalerror99/
When an object is assigned to itself, assignment to self occurs ):
Class widget {...};
Widget W;...
W = W; // assignment to self
This looks sil
First, make it clear:
The system has provided the default copy constructor and the = copy operator. That is, the so-called shallow copy.
But sometimes we have to provide our own rewrite. Generally, it is rewritten with pointers.
For a simple example, there is no pointer, so you don't have to rewrite it, just to demonstrate:
Class fraction {PRIVATE: int fenmu; // denominator int fenzi; // public: fraction (int x, int y) {fenzi = x; fenmu = y;} fractio
namespace std;Class CA{Public:CA (int B, char * cstr){A = B;Str = new char [B];Strcpy (str, cstr );}CA (const CA C){A = C.;Str = new char [a]; // deep copyIf (str! = 0)Strcpy (str, C. str );}Void Show (){Cout }~ CA (){Delete str;}Private:Int;Char * str;};Int main (){Ca a (10, "Hello! ");Ca B =;B. Show ();Return 0;}
Initializes an object by copying the status of another object of the same class.Usage: when passed through a value, return through a value, or explicitly copy an object
Value
Overloaded operators The overloaded operator is a function whose name is operator followed by its defined operator symbol. such as operator =, operator +, operator * and so on.The operator
. In fact, if two objects come from the same inheritance system, these two objects do not even have to be declared to be of the same type, because pointers or references to base classes can point to derived class objects:650) this.width=650; "src="/img/fz.gif "alt=" Copy Code "style=" Border:none; "/>1 class Base {...}; 2 3 class Derived:public Base {...};4 5 void DoSomething (const base RB,//RB and *PD might actually Be6 7 derived* PD); The same object650) this.width=650; "src="/img/fz.gif "alt
The following is a base class Bitmap and derived class widget, which defines a private-type pointer PBclass Bitmap {...}; class Widget { ... Private : // ptr to a heap-allocated object}; when overloading the assignment operator "=" in the Widget class, there are a few things to consider:1 Chain AssignmentThe first thing to consider is the case of a chained assign
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.