scala反转字符串

反转字符串 (Reversing a string)

Logically, reversing is swapping the values from index 1 with index n, index 2 with index n-1, and so on.

从逻辑上讲，反向是将索引1中的值与索引n交换，将索引2中的值与索引n-1交换，依此类推。

So, if the string is "IncludeHelp", then the reverse will be "pleHedulcnI".

因此，如果字符串为“ IncludeHelp” ，则反向为“ pleHedulcnI” 。

Example:

例：

Input:    String: "IncludeHelp"    Output:    Reversed string: "pleHedulcnI"

程序在Scala中反转字符串 (Program to reverse a string in Scala)

object myObject {
       def reverseString(newString: String): String = {
           var revString = ""        val n = newString.length()        for(i <- 0 to n-1){
               revString = revString.concat(newString.charAt(n-i-1).toString)        }    return revString    }    def main(args: Array[String]) {
           var newString = "IncludeHelp"        println("Reverse of '" + newString + "' is '" + reverseString(newString) + "'")    }}

Output

输出量

Reverse of 'IncludeHelp' is 'pleHedulcnI'

Another method will be to convert the string into a list and then reversing the list and the converting in back to the string.

另一种方法是将字符串转换为列表，然后反转列表并将其转换回字符串。

Program:

程序：

object myObject {
       def main(args: Array[String]) {
           var newString = "IncludeHelp"        var revString = newString.foldLeft(List[Char]()){(x,y)=>y::x}.mkString("")        println("Reverse of '" + newString + "' is '" + revString + "'")    }}

Output

输出量

Reverse of 'IncludeHelp' is 'pleHedulcnI'

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scala反转字符串