repeater trap

, arrays and objects such as compound variables generate a zval container for each item item when the Zval is generated. $array 1 Array (a); $x = $array 1// Unused reference$array 2$array 1// Reference now also applies to $array 2!//xdebug_debug_zval (' x '); Xdebug_debug_zval (' array1 '); Xdebug_debug_zval (' array2 '); Print_r ($array 1);(refcount=2, is_ref=0),Array (size=2)0 = (refcount=1, is_ref=0), int 11 = (refcount=2, is_ref=1), int 2Array2:(refcount=2, is_ref=0),Array (size=2)0

classMultviewcontroller {Private Static intst = 0;//of Static Private intindex = 0;//non-static@RequestMapping ("/show") PublicString toshow (Modelmap model) {User User=NewUser (); User.setusername ("Testuname"); User.setage ("23"); Model.put ("User", user); return"/lsh/ch5/show"; } @RequestMapping ("/test") PublicString Test () {System.out.println (St+ + + "|" + index++); return"/lsh/ch5/test"; }}0 | 01 | 12 | 23 | 34 | 4To multiple cases:0 | 01 | 02 | 03 | 04 | 0From this point, th

Analysis of the trap of JavaScript prototype inheritance Like other object-oriented languages, JavaScript uses the reference method for object types. The variable holding the object is only an address, while the basic type data is a value. There may be some traps when the prototype stores objects. By default, JavaScript uses prototype inheritance. Although there is no concept of a class, its function can act as a constructor ). The constructor can co

Javascript journey-site 8: Talking about instanceof stepping on a trapI encountered an instanceof trap when writing js a few days ago. An iframe exists in our page. I calculated an array in the index page, then we need to pass it to a function (SearchFlight) in the nested iframe on the Flight page. As a defensive programming, I need to perform parameter detection in the SearchFlight function, that is, the determined parameter must be of the Array type

Today, in running the first line of code Coolweather second stage code, another error, or magically similar to yesterday, hint, city_id field does not exist, here I have two kinds of understanding, one is the SQL statement error, the other is not get city_id value, about the former, I compared the "detailed" check, county Table statement, first ruled out, and then a brain put into how to solve the second problem, and finally, once again the tragic fact told me, as long as the hint "No such colu

Use of pointers1, define2,*ip storing the contents of the pointer in memory3,var variable var in memory address4,ip the address of the pointer variable5,var Defining variables#include using namespacestd;intMain () {int var= -;//declaration of the actual variable int*ip;//declaration of a pointer variableIP= var;//storing the address of Var in a pointer variablecout"Value of var variable:"; coutvarEndl; //output the address stored in the pointer variablecout "Address stored in IP variable:"; c

) { echo "key= $ke Y, value= $value ". Php_eol;} foreach ($array as $key = $value) { echo "key= $key, value= $value". Php_eol;}　　Key=name, Value=phpkey=age, Value=123key=name, Value=phpkey=age, value=php　　The value of the last line above is "PHP", not the 123 we expect, because in the second foreach Loop,Each time the loop is changed, the value of key ' age ' in $array is modified,In the first loop, the age in the array is already PHP (the first value), and in subsequent loops the last val

17:23:37.712 14978-14978/cn.codingblock.androidadvancestudy i/contactprovideractivity: Oncreate:phone = 13696969696As you can see, Zhuge Liang and the telephone number have been successfully added.Of course, in addition to the above several URIs, the system's ContentProvider interface has a lot of, not one example, use when you can query the official API.Finally want to say is, this series for Bo master on Android knowledge again comb, check the learning process, on the one hand is forgetting t

(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_my_view); myview = ViewUtils.find(this, R.id.myview); // 方案三、当 View 树的状态或者 View 树内部的 View 的可见性发生改变时， // ViewTreeObserver.OnGlobalLayoutListener 接口的 onGlobalLayout() 会被回调， // 可以在此方法内部获取 View 的尺寸 ViewTreeObserver observer = myview.getViewTreeObserver(); observer.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { @Override public void onGlo

', ' bbbb ']Print (Recursionsearch (targetdict, ' B ')) #{' Login ': {' Type ': ' LP ', ' Name ': ' 41ss676 ', ' Pwd ': {' AAA ': ' 12 3456 '}, ' Fortoken ': 1}}Print (Recursionsearch (targetdict, ' Login ')) #{' Type ': ' LP ', ' Name ': ' 41ss676 ', ' Pwd ': {' aaa ': ' 123456 '}, ' Fo Rtoken ': 1}Print (Recursionsearch (targetdict, ' Pwd ')) #{' aaa ': ' 123456 '}Print (Recursionsearch (targetdict, ' aaa ')) #123456The above can return the value of the correct target keyReverse test:Print (R

A strangeness problem was found today when converting byte[] to string and then back to byte[]. byte[] length has changed.The specific code is as follows:mapNewHashmap(); Map.put ("Cn1",NewPersion ("China 1", 30)); Map.put ("Cn2",NewPersion ("China 2", 30)); MapNewHashmap(); Classes.put (1, map); {Kryo Kryo=NewKryo (); Byteoutputstream Stream=NewByteoutputstream (); Output Output=NewOutput (stream); Kryo.writeclassandobject (output, classes); Output.flush (); byte[] bytes =

1.Java When creating an array, it is divided into two types, one static creation and one for dynamic creation. (1) statically created as string[] array = {"A", "B", "C"}; (2) dynamically created as string[] array = new string[] {"A", "B", "C"}; or string[] array = new STR ING[3];(First confirm the number of elements) in general the use of dynamic creation method is more flexible, you can first specify the number of elements after each element is assigned value. int a [+] , corrected

class.h, let the post Class1.h contain class.h, the last main.cc contains two class.h and Class1.h, and the last two header files are expanded simultaneously:g++-E main.cc > MAIN.EMain.eClass A{Publicvoid Printhello ();};# 2 "main.cc" 2# 1 "class1.h" 1# 1 "class.h" 1Class A{Publicvoid Printhello ();};# 1 "Class1.h" 2# 3 "main.cc" 2int main (int argc, char const *argv[]){A;A.printhello ();return 0;}We then main.cc inside the two Class A definition, this is certainly compiled, to avoid this multi

Whether you are applying for Python web development, crawler engineers, or data analysis, or automated operations, it involves some basic knowledge! I picked up some basic Python interview questions to see if you can answer them, maybe the students with the interview!Question 1: How can I modify the following Python code so that the following code calls the Show method of Class A?For:This topic examines the use of new and INIT, and using the new method, you can decide to return that object, whic

expression.byte,short,char--"int--" long--"float--" doublesuch as: short SV = 5; SV = Sv-2; The code will give an error in the second step because the expression result type on the right is automatically promoted to the int type, which cannot be assigned to the short SV at this time. If SV = Sv-2 is changed to SV-= 2, no error is expected. Because an implicit type reload is included in the review assignment operator. That is, SV-= 2, which is equivalent to SV = (short) (Sv-2), so if you use the

The Spring MVC controller defaults to Singleton:There are two reasons for a single case:1, for performance.2, do not need many examples.1, this does not have the nonsense, the single case does not need each time new, certainly fast.2, do not need an instance will confuse many people, because spring MVC official did not explicitly say can not be many examples.The reason why I don't need it here is to see how developers use it, and if you define a lot of attributes for the controller, then the Sin

parameter is bound at compile time.However, there are many other respondents who do not buy it and think that even first-class object the way it can be used is closure bound at execution time. This is a design flaw. It is a design decision; Perhaps a bad one and not a accident. The state thing are just like any and closure:a closure are not a function, and a function with mutable default argument is not a function. There is even a rebuttal of the realization of the logic, simply f

the collection set thinks that the object does not exist directly in the collection.When the object is changed in position, then the object to be added to the collection is compared with the object in the position.If Equals returns False, then the collection does not think that the object is recalculated Hashcode added in the collection;If Equals returns True, the collection does not add the object to the collection when it considers that the object already exists in the collectionSo when you r

; Public String GetName () { return name; } Public int Getage () { return age ; } }This question everybody knows actually is asks the reflection, in the Java inside class all members including public, private in front of reflection all can be invalid, is not think this reflection is too powerful ah! We can implement the modified field by using the following methods: 1. Syntax of the class, 2. Pass the GetClass () method of the Class object, and 3. The forna

place for the bed. Public Chouse (void); Virtual ~chouse (void); void Gotobed (); }; House.cpp #include "Bed.h" #include "House.h"//etc The house began to decorate, want to buy a bed Chouse::chouse (void) { bed = new CBed (); Put the bed in the house } Chouse::~chouse (void) { } void Chouse::gotobed () { Bed->sleep (); } Bed.h Class CBed { Public CBed (void); ~cbed (void); void Sleep (); }; Bed.cpp #include "Bed.h" cbed::cbed (void)