We know that there is a cross join in SQL Server 2000 that is used for interleaving. In fact, adding cross apply and outer apply is used to intersect table-valued functions (functions that return table result sets), and more importantly, the parameters of this function are fields in another table.--OUTER APPLYSELECT *From Table_1 T1Cross apply Fn_tablevalue (t1.c
Call is in order to change the context of a function, in other words, to change the direction of this inside the function. Because JavaScript has a "context of definition", "Runtime Context" and "context" can be changed. For example: var func1 = function (Arg1, arg2) {};Can be passed Func1.call (this, arg1, arg2); Or func1.apply (this, [Arg1, arg2]); To invoke. Where this is the context you want to specify, he can have any JavaScript object (everythin
The example analyzes the call () and apply () methods in javascript, and the example analyzes the apply
1. method definition
Call method:Syntax: call ([thisObj [, arg1 [, arg2 [, [,. argN])Definition: call a method of an object to replace the current object with another object.Note:The call method can be used to call a method instead of another object. The call method can change the object context of a func
Summary of the application skills of the apply method in JavaScript and the apply Application Skills
Preface
Recently, I have been looking at the JavaScript design patterns, some of which are clever functions. Therefore, after some modifications are recorded here, some interesting functions written by myself are added. It is convenient for you to use it later. Let's take a look.
1. call using
Use C ++ 11 to implement C ++ 17 apply (Dynamic Array Used as function parameter) and apply Array
The title is incorrect. apply uses tuple as the parameter to call a function. This title is used to better adapt to search keywords.
Dynamic Arrays used as function parameters are more suitable for C ++ programs embedded in the script environment, such as lua or java
Differences between cross apply and outer apply:
Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->
Declare @ t table (Name: varchar (10 ))
Insert into @ T values ('zhang san ')
Insert into @ T values ('Li si ')
Insert into @ T values ('wang 'er ')
Insert into @ T values (null)
Declare @ T2 table (Name: varchar (10), course varchar (10), score: INT)Insert in
Declare
@ T
Table
(Name
Varchar
(
10
))
Insert
Into
@ T
Values
(
'
Zhang San
'
)
Insert
Into
@ T
Values
(
'
Li Si
'
)
Insert
Into
@ T
Values
(
'
Wang 'er
'
)
Insert
Into
@ T
Values
(
Null
) Declare @ T2 Table (Name Varchar ( 10 ), Course Varchar ( 10 ), Score Int ) Insert Into @ T2 Values ( ' Zhang San ' , ' Chinese ' , 74 ) Insert Into
Apply, call
In JavaScript, call and apply are meant to change the context in which a function is run, in other words, to change the direction of this inside the function body.
One of the big features of JavaScript is that the function has the concept of "definition-time context" and "Run-time context" and "context is something that can be changed."
First come a chestnut:
function fruits () {}
fru
Before learning apply (), we have to understand the role of this and how to use it, and refer to my previous article, "Fast Understanding the usage and pitfalls of this in JavaScript." Of course if you are already familiar with this information, then
Please look straight down.
The function of call () and apply () is very similar, except for the difference in parameter types to accommodate different usage sc
In JavaScript, call, apply, and bind are the three methods of a function object, and the main effect of these three methods is to change the this point in the functions so that the ' move to the flower ' effect can be achieved. This article will explain the three methods in detail and list a few classic scenarios.
Call (Thisargs [, args ...])
The method can pass a Thisargs parameter and a list of arguments, Thisargs specifies the caller of the func
In JavaScript, the point of this is dynamic, and it is possible to accidentally break this point in the process of writing a program, so we need a technique that can fix the meaning of this, so we have the three methods of call,apply and bind, To change the point of this inside the function body, because the function has the concept of "definition-time context" and "Run-time context" and "context can be changed"
The new Apply table operator applies the right table expression to each row in the left table expression. It does not compute that table expression as a join, and the apply must first compute the left expression logically. The logical order of this calculation input allows the right expression to be associated with the left-table expression.
Apply has two forms
Apply: When you pass one or more arguments to a variable (object) in parentheses, Scala turns it into a call to the Apply methodVal Array=array (1,2,3,4,5,6)Array (0), the operation of the first element of the array is converted to the array.apply (0) operation, which also explains why the Scala array value is not enclosed in parentheses, because it is also a method call.Anyobject ("Key1") will be converted
One, call (), apply (), bind () method
In JavaScript, a method is invoked to replace another object by calling or apply, changing the object context of a function from the initial context to the new object specified by Thisobj. The simple thing is to change the context in which the function executes, which is the most basic usage. The basic difference of two methods is that the parameters are different.
C
If you are learning JavaScript this free and changeable language in the process of experiencing this feeling, then from the beginning, please put down your "prejudice", because this is absolutely a new continent for you, let Javascrip slowly melt before a set of coagulation programming consciousness, inject new vitality!Well, to start with, understand the Javascrtipt dynamic transformation Run-time context characteristics, which is mainly embodied in the application, call two methods of use.Dist
If you haven't contacted a dynamic language, it will be a magical and weird feeling to understand JavaScript in a compiled language, because the things that are often impossible in consciousness happen, and even feel unreasonable. If you're learning JavaScript in a free and changing language, this is the way you feel. , then from now on, please put down your "prejudice", because this is absolutely a new continent for you, let Javascrip slowly melt before a set of coagulation programming consciou
Apply
Apply Functions over Array MarginsUse functions against column rows or columns
Apply (X, MARGIN, fun, ...)
Lapply
Apply a Function over a List or VectorUsing functions on lists or vectors
Lapply (X, fun, ...)
Sapply
Apply a F
Directory
First, Closure (Closure)
1.1, closures related issues
1.2, understanding the closures
Second, the object
2.1. Object Constants (literal)
2.2, take the value
2.3. Enumeration (traversal)
2.4, Update and add
2.5, the object of the prototype
2.6, delete
2.7, Packaging
Third, function
3.1. Parameter object (arguments)
3.2. Constructor function
3.3. Function call
3.3.1, call
3.3.2, apply
3.3.3, caller
3.3.4, callee
3.5. Execut
Talking about the use of call (), apply (), bind () in JavaScript
The use of Apply/call/bind in JavaScript has been vague, just to see this article. There is a clearer understanding of the differences and connections between the three. Here's a record and share it with you.
Call (Thisobj,arg1,arg2 ...), apply (Thisobj,[obj1,obj2 ...]) These two methods are non-
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