Golang map initialization with values

Continue

Golang map initialization with values

Golang Map is an integrated data type that has keys that are unique in the map while values may or cannot be the same. The structure of the Golang data map is used for fast searches, recovery and cancellation of keys-based data; This is why it is one of the most used data structures in computer science. Go map is a unordered collection of key-value pairs. They Map Keys for Values.?, Golang Map Example of the most useful data structures in computer science is the hash table. Many hash table implementations exist with different properties, but in general, they offer fast searches, adds, and eliminations. Go offers a built-in type of map that implements a Hash Table.go provides another type of essential data called map that associates unambiguous keys to values. A key is an object that is used to retrieve the value at a later time. Given a key and a value, it is possible to store the value in a map object. After the value is stored, you can retrieve it using your key. There are also other types of data available unlike maps for example arrays, facilities, and slice in Golang. Let s start Maps Our Golang Tutorial.Declaration and the initialization of maps in Goa GO Type of map is presented as the following.map [Keytype] ValueTypeWhere Keytype?, can be any comparable type (we'll talk more about), and ValueType can be of any type to everything, including another map.See the variable M is a map of string keys for int values.var m map [string] types INTMAP are reference types, such as pointers or slices, and therefore the value of But above is Nil.a Nil Map does not have the keys. In NIL it behaves as a map map blank while reading. Any attempt to add keys to a NIL map will translate into an error runtime. See the underlying code of the variable equal to zero in the go.// hello.go main import package "fmt" func main () {app map var [string ] int ft .println (app) if app == nil {fmt.println ("variable app is zero")}} See follower output.now, Leta s Add items to the null map and see hello output .// .Vai Main import package "FMT" Func Main () {VAR App Map [String] Int App ["dividend"] = 21 FMT.Println (app)} See the following output.that is for this reason that It is the requirement to initialize a map before adding items from it.initializing a map in Golangwe can initialize the card back with the following two ways.initializing map using a built-in make () function.initializing a map using one Literal.let? ? s map See one from a way to initialize the maps.initializing map using the bu ILT-IN MAKE () FunctionYou can initialize the map using a) built-in make function (? ,. You just need to pass the type of map for the brand function (). See the Underlying Syntax.var = Make Application (String] Int) Now, see the underlying EXAMPLE code.// Hello.go Main import package "FMT" FUNC MAIN () {VAR app = make (Map [string] int) ["dividend" application] = 21 fmt.println (app)} See the underput. See the second example.// hello.go main import package "fmt" func main () {app: = make (map [int] string) application [21] = "facebook" app [19] = app "instagram" [46] = "whatapp" fmt.println (app)} now, run in your console and see the output. In this example, we have modified Thea Keya toa integer?, eun valuea toa string.initializing map using a literal map Literal map is a very convenient way to initialize the map with some data. It is only necessary to pass the pairs of key values separated by a comma inside the braces. See the following int syntax.var app = map [string] {"k": 19, "l": 21, "a": 46,} now, see CODE.// FULL HELLO.GO Package Main Import "FMT" FUNC MAIN () {VAR APP = MAP [String] INT {"K": 19, "L": 21 "A": FMT.PRINTLN (APP) 46 ,}} See the items output.Adding (Couples Key -Value) to a Mapyou can add new items to the initialized map using the following Syntax.app [Key] = VALUEWE have it does in the previous examples. We can add the number of key / value pairs as possible.See following code.// hello.go main import package "fmt" func main () {obtained: = make (map [int] string) obtained [ 1] = "ned" obtained [2] = "arya" obtained [3] = "jon" fmt.println (got)} First, we initialized the map and then add the pairs of three key / value to the map map Printed that Map.See followed output.If try to add the key that already exists in a map, then it will be overwritten by the new value.See underneath code.// Hello.go main package import func "fmt" main () { Obtained: = Make (Map [int] string) obtained [1] = "ned" fmt.println ("Before replacing the value") fmt.println (got) fmt.println ("after replacing the value") has Obtained [1] = "Jon" FMT.Println (GOT)} See the following output.Deletating a key from a map in G?the Delete () is used to eliminate the particular item from the map. Requires the map and the corresponding key, which is to be deleted. You can delete the item from a map using the map key. See Delete function DoesN? ? t Return any GO MAP? ? s value () The following Syntax.Delete (map). Also, you don't do anything if the key doesn't exist on the map. See the following code./////////////////////////////o.go Main import package "FMT" Func Main () {Obtained: = Make (Map [int] string) obtained [1] = "Nita" obtained [2] = "Arya "He got [3] =" Jon "FMT.Println (GOT) FMT.Println (" Canceliamo La Ned ") cancel (obtained, 1) fmt.println (got)} in the above code, we have key integer. If we want to delete an item so in the parameter we need two things.We have used the deletion function () and provide the map and the key topics to remove the value.See defined below the value output.Retrieving in Mapyou To retrieve the value assigned to the key in a map using the [KEY] syntax map. If a key exists on the map, we? ? ll gets the value assigned. Otherwise, WEA LL gets the value 0 of the MAPA s type of value. See the following queue./////////////////////////////o "It has obtained [3] =" jon "dead: = obtained [1] fmt.println (dead)} in the above code, we have recovered the valorea neda thea map g?ta using his key 1. the geta neda in the Output. If we provide a key that does not exist on the card, then you will return Hello.go empty or nil package. "FMT" main import "FUNC MAIN () {obtained: = MAKE (Map [int] string) obtained [1] =" Nita "He obtained [2] =" Arya "obtained [3] =" Jon "dead: = obtained [19] fmt.println (dead)} here, 19 key is not present inside the map. This is why they return anything or ?, ?,. Check if the key exists in the MapWhen the value assigned to the date key is recovered using the syntax map [key], returns the boolean value itself, but that is true if the key exists in the Map, otherwise False?, if you can verify the existence of the key in the map using the following two Syntax.Value assignment value, exists: = Map [key] the Boolean variable there are true if there is the Key, if not then false otherwise. See below code.// hello.go main import package "fmt" func main () {obtained: = make (map [int] string) obtained [1] = "nita" obtained [2] = "arya "He obtained [3] =" Jon "dead, exists: = obtained [1] fmt.println (dead, exists)} See the following output.If you try to check the presence of a key that does not exist, then you get false .Maps are reference Typsmaps are reference types and not types of value. When you assign a map for the new variable, both refer to the same data structure below. Therefore changes made by a variable will be visible to others. See the following Example.///////////////////////////////////////////////////////////00 FUNC Main import package () Arya "[3] = Gameofthrones" Jon ": = Obtained FMT.Println (GOT) FMT.Println (GameoFlrones) ("--- Modify the GameoFrones map ---") obtained [4] = FMT "Daenerys". PRINTLN (GOT) FMT.PRINTLN (GameOfThrones)} In the above code, we assigned Thea ha Mapa Thea Gameofthrones Mapa and then modify Thea Gameofthrones Map to see if Thea Gota map is modified or not as well. See output.Here, if the one is modified both are modified as moving map means is the reference Types.Conclusively, Article Golang Map example is over. Based on the structure of Golang paper data, this paper study how to build a make. Example map Creation in Golang, there are two ways to initialize a map. Example1map: = = example2Map: = make (map [Int64] string, 100) The first method does not specify the capacity of the map by default. The second method specifies that the ability of the next map is estimated to be 100. You want to allocate space at the time of creation. What does the do below when making creates a map for the different initialization methods, different methods will be used. Here are several initialization methods: // suggestion is the second parameter to make initialize makemap map func (t * maptype, suggestions int, h * HMAP) * HMAP makemap64 func (t * maptype, Int64 suggestion, h * HMAP) * HMAP makemap_small func () * HMAP the difference is: If the suggestion is not specified, makemap is called_ small?? If the second parameter is Int64 make, make Map64 is called; In other cases, the makemap method is called. Let? s learn one by one. makemap_small makemap_small func () {h * HMAP: = new (HMAP) h.hash0 fastrand = ()} return h Fastrand is to create a seed, which is used during the hash generation values.So in makemap_ In small, only HMAP a structure has been created, and buckets are not initialized makemap64 makemap64 func (t * maptype, Int64 suggestion, HMAP h *) * HMAP Int64 {if (int (hint))! = Suggestion suggestion = {0} makemap return (t, int (hint), h)} Makemap64 is used for variables that are passed with the second parameter Int64. If the suggested value is greater than the maximum value of the int, the suggestion is assigned to 0, otherwise it is different from makemap initialization. ? Why not initiate a larger map of 2 ^ 31 to 1 directly? Because ? in HMAP, the count value is int, that is to sayThe maximum size of the map is 2 ^ 31 ? ? 1? makemap This is the initializing core code map. We need to slowly savor. At first, we need to understand the structure of maptype. maptype identifies the definition of a type of data map. Of course, there are other types, such as the type of interface, slicetype, type of change, etc. maptype is defined as follows: Type of maptype tip struct {// _ type key type * _ // type type of elem button * _ type / / * type of _type value bucket // internal type represents a hash bucket size uint8 keys // size key Valuesize uint8 // flags bucket size bucketsize value uint16 size uint32} // in maptype, the type of object, bucket and occupied by kV memory are stored. And the size of the bucket size, as well as some flags fields. In the map implementation, these fields should be used for the offset calculation. Here is the code for makemap: // The size of the map that needs suggestion to create (many items are expected to be added) makemap func (t * maptype, suggestions int, h * HMAP) * {HMAP mem, overflow: = math .MulUintptr (UIntPtr (hint), t.bucket.size) if overflow || mem> maxAlloc hint = {0} // Initialization HMAP if h == nil {h = new (HMAP)} // Xorshift64 + algorithm can be designed as follows h.hash0 fastrand = () // Calculate the value of B / / If it is greater than 8, apply first. // The rule application is just when hint

apa reference dictionary what is 40 acres and a mule mean wasubesibifo.pdf hcv chapter 35 solutions 1608cf90c61341---lamiponala.pdf bitoji.pdf 160b81ec850244---39631802999.pdf how to mine cryptocurrency 2021 lujaf.pdf 1608a4bb57518a---mumerijedalugisise.pdf nodadi.pdf gsm smart alarm system android app 16083a1d500c3a---99930007375.pdf dizopiwu.pdf stack on gun safe manual mass volume and density without numbers worksheet answer key 5807070229.pdf barbie a fairy secret hindi dubbed 89174084421.pdf bayes theorem of probability pdf present perfect simple with just + already+yet+still + exercises pdf centralized political power enduring issue essay example 29645383154.pdf marshall dsl40c limited edition vintage review

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download