testpassbyvalue.java

此源码为机械工业出版社出版的《Java语言程序设计》第三版所配套的书中所有源代码。

// TestPassByValue.java: Demonstrate passing values to methods
public class TestPassByValue
{
  // Main method
  public static void main(String[] args)
  {
    // Declare and initialize variables
    int num1 = 1;
    int num2 = 2;

    System.out.println("Before invoking the swap method, num1 is " +
      num1 + " and num2 is " + num2);

    // Invoke the swap method to attempt to swap two variables
    swap(num1, num2);

    System.out.println("After  invoking the swap method, num1 is " +
      num1 + " and num2 is " + num2);
  }

  // The method for swapping two variables
  static void swap(int n1, int n2)
  {
    System.out.println("    Inside the swap method");
    System.out.println("    Before swapping n1 is " + n1
      + " n2 is " + n2);

    // Swapping n1 with n2
    int temp = n1;
    n1 = n2;
    n2 = temp;

    System.out.println("    After  swapping n1 is " + n1
      + " n2 is " + n2);
  }
}