2 Language Fundamentals

2.1	The following program will compile and run without errors: package com.acme; // Correct ordering of package and import statements. import java.util.*; public class Exercise1 { int counter; // This is rather useless public static void main(String[] args) { // Correct main signature Exercise1 instance = new Exercise1(); instance.go(); } public void go() { int sum = 0; // We could just as well have written sum = 100 // here and removed the if statement below. int i = 0; while (i<100) { if (i == 0) sum = 100; sum = sum + i; i++; } System.out.println(sum); } }
2.2	The following program will compile and run without errors: // Filename: Temperature.java /* Identifiers and keywords in Java are case-sensitive. Therefore, the case of the file name must match the class name, the keywords must all be written in lowercase. The name of the String class has a capital S. The main method must be static and take an array of String objects as an argument. */ public class Temperature { public static void main(String[] args) { // Correct method signature double fahrenheit = 62.5; // /* identifies the start of a "starred" comment. // */ identifies the end. /* Convert */ double celsius = f2c(fahrenheit); // '' delimits character literals, "" delimits string literals System.out.println(fahrenheit + "F = " + celsius + "C"); } static double f2c(double fahr) { // Note parameter type return (fahr - 32) * 5 / 9; } }