JAVA程序片段.docVIP

基本语法 ① // Addition program that displays the sum of two numbers. 3 import java.util.Scanner; // program uses class Scanner 5 public class Addition 6 { 7 // main method begins execution of Java application 8 public static void main( String args[] ) 9 { 10 // create Scanner to obtain input from command window 11 Scanner input = new Scanner( System.in ); 13 int number1; // first number to add 14 int number2; // second number to add 15 int sum; // sum of number1 and number2 17 System.out.print( Enter first integer: ); // prompt 18 number1 = input.nextInt(); // read first number from user 20 System.out.print( Enter second integer: ); // prompt 21 number2 = input.nextInt(); // read second number from user 23 sum = number1 + number2; // add numbers 25 System.out.printf( Sum is %d\n, sum ); // display sum 27 } // end method main 29 } // end class Addition Enter first integer: 45 Enter second integer: 72 Sum is 117 ② public class GradeBook { public void displayMessage() { System.out.println( Welcome to the Grade Book! ); } } public class GradeBookTest { public static void main( String args[] ) { GradeBook myGradeBook = new GradeBook(); myGradeBook.displayMessage(); } } Welcome to the Grade Book! ③ String nameOfCourse = input.nextLine(); // read a line of text ④ depositAmount = input.nextDouble(); // obtain user input while ( input.hasNext() ) 58 { 59 grade = input.nextInt(); // read grade 60 total += grade; // add grade to total 61 ++gradeCounter; // increment number of grades 63 // call method to increment appropriate counter 64 incrementLetterGradeCounter( grade ); 65 } // end Figure 6.2. Math class methods Method Description Example abs( x ) absolute value of x abs( 23.7 ) is 23.7abs( 0.0 ) is 0.0abs( -