How to use mkString in Scala

This article mainly introduces "the specific use of mkString in Scala". In the daily operation, I believe that many people have doubts about the specific use of mkString in Scala. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful to answer the doubts about "the specific use of mkString in Scala". Next, please follow the editor to study!

Use of the 1.mkString () method:

The mkString (seq:String) method splits the original string with a specific string seq. The mkString (statrt:String,seq:String,end:String) method splits the original string with a specific string seq, adding the string start before the original string and the string end after it.

Object Test {def main (args: Array [String]): Unit = {var name: String = "Hello LittleLawson" var age: Int = 2 println (name.mkString) println (name.mkString (")) / / separate string with space var str0 =" scala "println (str0.mkString (", ")) / / separate string with comma println (str0.mkString (" begin "," end ")) / * 1.mkString is used in the inner List,That is say, Elements in the list is applied. * / val a = List val b = new StringBuilder () println (a.mkString ("List (", ",")}}

The execution results are as follows: Hello LittleLawsonH ello LittleLawso ns,c,a,l,abegins,c,a,l,aendList (1,2,3,4)

Process finished with exit code 0

2.scala converts a collection into a string through the mkString method.

Problem if you want to convert collection elements to strings, you may also add delimiters, prefixes, and suffixes.

Solution uses the mkString method to print a collection. Here's a simple example:

Scala > val a = Array ("apple", "banana", "cherry") a: Array [String] = Array (apple, banana, cherry) scala > a.mkStringres3: String = applebananacherry

Using the mkString method, you will see that the result is not beautiful. Let's add a delimiter:

Scala > a.mkString (",") res4: String = apple,banana,cherryscala > a.mkString (") res5: String = apple banana cherry

It looks much better this way, and you can also add a prefix and a suffix:

Scala > a.mkString ("[", "]") res6: String = [apple, banana, cherry]

If you want to convert an escape set into a string, such as a nested array, first expand the nested array, and then call the mkString method:

Scala > val a = Array (Array ("a", "b"), Array ("c", "d")) a: array [Array [string]] = Array (Array (a), Array (c) scala > a.flatten.mkString (",") res7: String = a line bline d

Discussion

You can call the collection's toString method, but it returns the collection name with the collection element information:

Scala > val v = Vector ("apple", "banana", "cherry") v: scala.collection.immutable.Vector [String] = Vector (apple, banana, cherry) scala > v.toStringres8: String = Vector (apple, banana, cherry)

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