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Scala_1.控制台打印，变量定义，函数定义

package com.liusimport scala.util.control._object HelloWorld {  def main(args: Array[String]): Unit = {////    printStr()                   //打印输出//    variablePractice()           //变量练习//    strOperation()               //字符串操作//    println(functionName(12,5))  //函数操作  }  /**   * 打印练习   */  def printStr():Unit={    println("Hello World!")    println(10)    print("Hello World!")  }  /**   * 变量练习   */  def variablePractice():Unit={    val x =10    var y = 10    y =20    val z:Int = 10    val a:Double = 1.0    val b:Double = 10.0    println("Hello World".length)    println("Hello World".substring(2,6))    println("Hello World".replace("H","3"))    println("Hello World".take(5))  //Hello    println("Hello World".drop(5))  // World  }  /**   * 字符串操作   */  def strOperation():Unit={    //s""    val  n = 45    println(s"We have $n apples")    val c = Array(11,9,6)    println(s"My Second daughter is ${c(0)-c(2)} years old.")    println(s"We have double the amount of ${n/2.0} in apples.")    println(s"Power of 2:${math.pow(2,2)}")    //f""    println(f"Power of 5:${math.pow(5,2)}%1.0f")    println(f"Square of 122:${math.sqrt(122)}%1.4f")    //raw""    println(raw"New line feed:\n.Carriage return:\r.")    println("They stood outside the \"Rose and Crown\"")    val html =      """       
    
       
     
Press belo',Joe
       
            
    
      """    println(html)  }  /**   * 函数练习   * @param a   * @param b   * @return   */  def functionName(a:Int,b:Int):Int={//    println(a+b)    return a+b;  }}