olzconcept.blogg.se - Starting out with java 7th edition pdf free download

Returning Objects from MethodsĪ method can return a reference to an object.Starting Out With Java 7Th Edition Pdf Free Download. When writing a method that receives the value of a reference variable as an argument you must take care not to accidentally modify the contents of the object that is referenceing the variable. When a reference variable is passed as an argument to a method, the method has access to the object that the variable references. When the method changes the contents of the parameter variable it does not affect the contents of the original variable that was passed as an argument. Passed by value - when a varaible is passed as an argument to a method. Kilometers = Metric.milesToKilometers(10.0) String names = public static double kilometerrsToMiles(double k) String ArraysĪn array of String objects may be created, but if the array is uninitialized, each String in the array must be creaed individually. P.487 In addition to accepting arrays as arguments, methods may also return arrays. Partially Filled Arrays & Working with Arrays & Files While (number = 1 & number numbers.length index++) Input validation - a while loop can be used to create input routines that repeat until acceptable data is entered

It will never iterate if the Boolean expression is false A statement or block of statements that repeats as long as the expression is true. Header: BooleanExpression is any valid Boolean expressionīody: Any valid Java statement. Pretest loop - tests the Boolean expression before an iteration User controlled loop - allows the user to decide the number of iterations While Loop - pretest loop Infinite loop - if a loop does not have a way of stopping it continues to repeat until the program is interrupted Loop control variable - controls the number of time that the loop iterates This is usually done by incrementing the variable.

it must update the control variable during each iteration.

When the control variable reaches its maximum value, the loop terminates

must test a control variable by comparing it to a maximum value.

must initialize a control variable to a starting value.

Increment operator - increase value by one number++ number++ = number = number + 1 ĭecrement - decrease value by one number- = number = number - 1 Ī loop is a control structure that causes a statement or group of statements to repeat 2 Kinds of LoopsĬonditional Loop - executes as long as a particular condition existsĬount-Controlled Loop - a loop that repeats a specific number of times Primitive data types - you use these data types to create variables which are storage locations in the computer's memory - they have no other built in capability other than storing a value.īyte short int long char float double boolean Chapter 4 Increment & Decrement Starting Out with Java 4th Edition - Tony Gaddis