"Learn Scala" chapter II Problem solving

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Package Com.scalalearn.scala.main/** * Learn Scala 02 exercises */Object LEARNSCALA02 {//1. If a number is positive, its signum is 1; if it is negative, SIGNU 

  M is-1; if it is 0, then Signum is 0//write a function to calculate the value def execise1 (num:int): Int = {if (num > 0) 1 else if (num = = 0) 0 Else-1} 2. What is the value of an empty block expression. What is its type//value is (), the type is unit//3. It is pointed out that Scala is the case that the assignment statement X=y=1 is legal//is legal//4 in the case of the type of x for the unit. Write a scala version of//for for the following Java loops (int i
      =10;i>=0;i--) System.out.println (i) def execise4 (): unit={var i = ten while (i >= 0) {println (i) i = I-1}}//5. Write a procedure countdown (N:int), print a number from N to 0 def countdown (n:int): unit={var i = n while (i >= 0 {println (i) i = i-1}}//6. Write A For loop that calculates the product of the Unicode code for all the letters in the string//For example, the word literal for all letters in "Hello" is 9415087488 L def execise6 (input:string): BigInt = {var sum:bigint = 1 val length = Input.length for (i <-0 to length -1) {sum = sum * input (i). Tolong} sum}//7. The same is the problem of solving 6, but not enough to cycle (hint, stringops) def execise7 (Input:strin G: BigInt = {var Sum:bigint = 0 sum = Input.map (_.tolong). Product sum}//8th feel and 6,7 Repeat, so do not//9. Put the previous practice letter The number is changed to the recursive function Def execise9 (input:string,curindex:int): BigInt = {if (Curindex = = input.length-1) {input (Curindex). Tolong} else{execise9 (input,curindex+1) *input (Curindex). Tolong}}//10th, title is too long, mainly by definition write function def exec Ise10 (x:double,n:int): BigDecimal ={if (n = = 0) {1}else if (N < 0) {1/execise10 (x,-1*n)}else if (n% 2 = = 1) {x*execise10 (x,n-1)}else{execise10 (X,N/2) *execise10 (X,N/2)}} def main (Args:ar Ray[string]): Unit = {println ("================execise1==============") println (Learnscala02.execise1 (333)) PR Intln (Learnscala02.execise1 ( -23)) println (learnscala02.execise1 (0)) println ("================execise4===========

    = = = ") Learnscala02.execise4 () println (" ================execise5============== ") Learnscala02.countdown (3) println ("================execise6============== ") println (Learnscala02.execise6 (" Hello ")) println (" ================execise7============ = = ") println (Learnscala02.execise7 (" Hello ")) println (" ================execise9============== ") println (learns Cala02.execise9 ("Hello", 0)) println ("================execise10==============") println (Learnscala02.execise10 (2,
 -4)}}