First, the foregoing
The functions in Scala are still more important, so this article enumerates the functions that may be used in Scala and explains them in detail.
Second, the specific function
1, the definition of Scala function
def fun (A:int, b:int): unit = {
println (a+b)
}
Fun (1,1)
def fun1 (a:int, b:int) = A+b
printl N (fun1 (1,2))
No
Let's look at a loop in Java: for (int i = 1; i ) { + ",");}There is no doubt that Scala can make this loop more concise. According to the previous section, it is not necessary to display the type of the specified variable i, and we do not even need to declare the variable. The next output statement can be more concise, and in Scala you can use the println () method to output a string directly. Finall
Package Com.leegh.parameterizationImport Com.leegh.parameterization.Compound_Type/*** @author Guohui Li*/Trait Compound_type1;Trait Compound_type2;Class Compound_type extends Compound_type1 with compound_type2Object Compound_type {def compound_type (x:compound_type1 with compound_type2) = {println ("Compound Type in Global Method")}def main (args:array[string]): Unit = {Compound_type (new compound_type1 with Compound_type2)Object Compound_type_object extends Compound_type1 with compound_type2Com
Package Com.leegh.parameterization/*** @author Guohui Li*/Class Pair_ordering[t:ordering] (Val first:t, Val second:t) {def bigger (implicit ordered:ordering[t]) = {if (Ordered.compare (first, second) > 0) First Else second}}Object Context_bounds {def main (args:array[string]): Unit = {Val pair = new pair_ordering ("Spark", "Hadoop")println (Pair.bigger)Val pairint = new Pair_ordering (3, 5)println (Pairint.bigger)}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be ed
We do spark development using a lot of spark's higher-order functions so today I'm using scala higher-order functions on Linux ServicesDeclares a list collection:The package containing the list is already automatically introduced by the predefined, so there is no need to introduce a package here, directly using the list instantiation object, actually using the list object object's Apply methodWe use the map function to multiply each value in the list
public number is Dt_spark, every day will have big data actual combat video release, please continue to study.Liaoliang DT Big Data dream factory Scala all videos, PPT and code in Baidu Cloud disk link:http://pan.baidu.com/share/home?uk=4013289088#category/type=0 Qq-pf-to=pcqq.groupLiaoliang "Scala Beginner's introductory classic video course" http://edu.51cto.com/lesson/id-66538.htmlLiaoliang "
Package Com.leegh.parameterization/*** @author Guohui Li*/Class PersonClass Student extends PersonClass C[+t] (Val args:t)Trait Friend[-t] {def makefriend (Somebody:t)}Object Variance {def makefriendwithyou (S:student, f:friend[student]) {f.makefriend (s)}def main (args:array[string]): Unit = {Val Value:c[person] = new C[student] (new Student)}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaoliang teacher, what to gain, so recommend.3. Blog focus on
In the first two sections, we learned about Scala's objects and associated objects, both of which are used to mean the static members of Java. There are no static fields and static methods in Scala. A static member destroys the complete object-oriented model that Scala supports. However, it is possible to implement class-level operations on Scala through the asso
Package Com.leegh.parameterization/*** @author Guohui Li*/Class Pair[t def bigger = if (First.compareto (second) > 0) First Else second}Class Pair_lower_bound[t] (Val first:t, Val second:t) {def Replacefirst[r;: T] (newfirst:r) = new Pair_lower_bound[r] (Newfirst, second)}Object Type_variables_bounds {def main (args:array[string]): Unit = {Val pair = new pair ("Spark", "Hadoop")println (Pair.bigger)}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaol
First, prefaceThe Scala program uses Unicode's BMP character set (Wiki:bmp character set), which is not currently supported by the Unicode supplement character set. This chapter defines Scala's syntactic analysis from Scala models and XML models. If not specifically mentioned, the default refers to the Scala model and specifies that the characters are ASCII \u000
Scala code in one day (7) and scala code in one dayScala code in one day (7)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful.
Package examplesclass Angela {// package visibility This specifies that this method
Scala code in one day (9) and scala code in one dayScala code in one day (9)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful.
Package examplesimport scala. io. sour
Scala Learning six: special characters in Scala
special characters in Scala instructions for use:
Object Scalaoperator {def main (args:array[string]) {///::: Three colons: 2 collections merged println ("-------[:::]") Val list1 = List (1, 2) Val list2 = List (3, 4) Val listcombine = List1::: List2 Listcombin
E.foreach (x = {println (x)}) println ("-----
Package Com.leegh.parameterization/*** @author Guohui Li*/Object Type_contraints {def main (args:array[string]): Unit = {def Rocky[t] (i:t) (implicit ev:t println ("Life is too short,you need spark!")}Rocky ("Spark")}}Report:This blog description:1. Organize your ideas and improve yourself.2. Be educated in Liaoliang teacher, what to gain, so recommend.3. Blog focus on practice, superfluous words are not much to say, are doing technology.4. Information from DT Big Data Dream Factory public accou
650) this.width=650; "src=" Http://s3.51cto.com/wyfs02/M01/6F/91/wKioL1WhEYHR0V55AAi8dfKDnAg782.jpg "title=" 002- Scala function definition, Process Control, exception handling get started in combat. png "alt=" wkiol1wheyhr0v55aai8dfkdnag782.jpg "/>002-scala function definition, Process Control, exception handling getting started combatScalafunction Definitionstatement end no semicolondefining an parameter
3, hands-on generics in Scalageneric generic classes and generic methods, that is, when we instantiate a class or invoke a method, you can specify its type, because Scala generics and Java generics are consistent and are not mentioned here. 4, hands on. Implicit conversions, implicit parameters, implicit classes in Scalaimplicit conversion is one of the key points that many people learn about Scala, which i
Scala code in one day (5) and scala code in one dayScala code in one day (5)To better control spark, I recently studied scala language features, mainly reading "quick learning scala" and writing down some codes that I think are useful.
Package examplesclass Person {val publicVal = 1 // automatically generate getter var
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