Announcements Exam 1 Thursday 50 minutes 10 % of Total Grade Covers Everything through Lecture Last Week Quiz 1 Topics (terminology, variables, constants, basics) if-then-else Compound statements Relational operators Logical operators Switch/Case Statements
Iteration Iteration (Looping): Performing a Series of Statements Multiple Times until Some Condition Is Met. Eliminates the Need for Redundant Coding or Function Calls Many Ways to Loop in JAVA
The while Loop Syntax: while (condition) statement; while (condition) { statement; }
while Example final int MAX = 100; int counter = 0; while (counter < MAX) { System.out.println( counter + “ “ ); counter++; }
Example while Loop int numEmployees,curNum = 0; System.out.print(“Enter Number of Employees: “); numEmployees = scan.nextInt(); if (numEmployees > 0) { while (curNum < numEmployees) System.out.println( “Welcome to CorpLand!” ); curNum++; }
The for Loop Syntax: Same as: for (expression1;condition; expression2) statement; { } Same as: expression1; while (condition) expression2;
Example for Loop System.out.println( “Welcome to CorpLand!” ); } int numEmployees,curNum; System.out.print(“Enter Number of Employees: “); numEmployees = scan.nextInt(); if (numEmployees > 0) { for (curNum = 0; curNum < numEmployees;curNum++) System.out.println( “Welcome to CorpLand!” ); }
Looping for Input char letterEntered = ‘A’; String stringE; while (letterEntered != ‘Z’) { System.out.print(“Enter a letter: “); stringE = scan.next(); letterEntered = stringE.charAt(0); }
Looping until Flag boolean noMoreData(); boolean done = false; … while (!done) { // do a bunch of stuff if (noMoreData() == true) done = true; } System.out.println(“ We’re all through – thank you!”);
Nested Loops int i , j ; for (i=0; i < 10; i++) { for (j=0; j < 10; j++) System.out.print(i); System.out.print(j); System.out.print(“ “ ); } System.out.println();
The do-while Loop Syntax do statement; while (condition); { }
do-while Example char letterEntered; String stringE; do { System.out.print(“Enter a letter: “); stringE = scan.next(); letterEntered = stringE.charAt(0); } while (letterEntered != ‘Z’);
What Is This? while (!stringEntered.equals(“apple”)) { System.out.println( “Enter a red fruit: “); stringEntered = scan.next(); } while (!stringEntered.equals(“banana”)) System.out.println(“Enter a yellow fruit: “); while (!stringEntered.equals(“pomegranate”)) System.out.println(“Enter a random fruit: “);
What Is This? for (i = 0; i < 10 ; i++) System.out.println( “Interesting, isn’t it?”); while (answer.charAt(0) != ‘D’) { System.out.print( “Enter an answer: “); answer = scan.next(); }
What Is This? void kingsChair(int loopCounter) { int num; for(num = 0; num < loopCounter; num++) System.out.println(“AAAAAAAAAAAAAAAAAAAAAAAAAA”); }