华南理工大学大一JAVA复习题.doc

2.1从输入对话框读入double型的华氏度，将其转换为摄氏度，并在消息对话框中显示结果。 Celsius = (5/9)*(Fahrenheit-32) import javax.swing.JOptionPane; public class Exercise2_1 { public static void main(String[] args) { String fahrenheitString = JOptionPane.showInputDialog(null, Enter a temperature in fahrenheit:, Exercise2_1 Input, JOptionPane.QUESTION_MESSAGE); double fahrenheit = Double.parseDouble(fahrenheitString); double celsius = (5.0 / 9.0) * (fahrenheit - 32); System.out.println(The temperature is + celsius + in Celsius); System.exit(0); } } 2.7编写程序将大写字母转换为小写字母，该字符在源代码ASCII中指定为直接量。 public class Exercise2_7 { public static void main(String[] args) { char uppercase = F; int offset = (int)a - (int)A; char lowercase = (char)((int)uppercase + offset); System.out.print(The lowercase letter is + lowercase); } } 3.1 （三角形有效性验证）读入三角形的三条边并确定输入是否有效。如果任意两条边和大于第三边则输入有效。 import javax.swing.JOptionPane; public class Exercise3_1 { public static void main(String[] args) { String numberString = JOptionPane.showInputDialog(null, Enter the first edge length (double), Exercise3_1 Input, JOptionPane.QUESTION_MESSAGE); double edge1 = Double.parseDouble(numberString); numberString = JOptionPane.showInputDialog(null, Enter the second edge length (double), Exercise3_1 Input, JOptionPane.QUESTION_MESSAGE); // Convert string to double double edge2 = Double.parseDouble(numberString); numberString = JOptionPane.showInputDialog(null, Enter the third edge length (double), Exercise3_1 Input, JOptionPane.QUESTION_MESSAGE); double edge3 = Double.parseDouble(numberString); System.out.println(Can edges + edge1 + , + edge2 + , and + edge3 + form a triangle? + ( (edge1 + edge2 edge3) (edge1 + edge3 edge2) (edge2 + edge3 edge1))); System.exit(0); } } 4.1 （千克转换成磅）编一个显示下列表格的程序（1千克为2.2磅） (1kilogram = 2.2 pounds) Kilograms Poun