How I'm supposed to write out the statement.
I am fairly certain that I should be making variable "b" and "c" a float. But beyond that I'm confused.
uploadfromtaptalk1407333378833.jpg
I understand how mixing expressions of different data types can result in an error if the assigned variable is not the same data type. But I don't understand how the below causes an error:
short totalPay, basePay = 500, bonus = 1000;
totalPay = basePay + bonus; // This causes the error
500 + 1000 = 1500. 1500 falls within the short parameters. If basePay, bonus, and totalPay are all short, as well as the resulting equation, how is this erroring?
I have an int array that has information read from a file. Now i want to display this int on a jtable but ofcourse i cant display primitive data types.. and also you cannot cast an int[] to an Object[], so I am stuck...
View Replies View RelatedTrying to find a way to use primitive data types to overload sound()method. I can't seem to warp my head around using an int or a double to overload the method. And if I did, how do you call them in the main afterwards?
View Replies View RelatedI get an error when I try to divide 500 miles by 25.5 gallons
Exception in thread "main" java.lang.NumberFormatException: For input string: "25.5"
at java.lang.NumberFormatException.forInputString(Num berFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:580)
at java.lang.Integer.parseInt(Integer.java:615)
at Mileage.main(Mileage.java:42)
Java Result: 1
[Code] .....
I am reading a book on Java and we are at a point where it is explaining type conversion in expressions. One of the examples shared has a byte being multiplied by itself and then assigned back to itself ...
byte b;
b = 10;
b = (byte) (b * b);
this is all good and dandy (that is, the code functions properly).
However, I am confused why I need to typecast here! Without the cast, the compiler screams, "Type mismatch: cannot convert from int to byte." Yet I haven't converted to an int?? It appears there was an implicit conversion.
The final value, 100, is clearly within byte's range of -127 to +127 isn't it? So I am lost as to what is the issue here.
Why the following is happening.
For the below code, when I execute it, it prints
Short method 10 //result 1
Sub class short method 10 //result 2
Which is as expected but if I comment out line 3, then it prints
Integer method 10 //result 3
Integer method 10 //result 4
I can understand result 3 is because of an upcast from short to int, since FunWithOverloading will not have a overloaded method with short now. However, what is happening with result 4? Shouldn't it call methodA of the subclass with the argument type short? If its because I have declared the reference variable, derived, of the type FunWithOverloading, then how come the first result correctly picks the overloaded method of the sub class?
class FunWithOverloading{
void methodA(int x){System.out.println("Integer method " + x);}
void methodA(short x){System.out.println("Short method " + x);} //line 3
} class OverloadedSubClass extends FunWithOverloading{
void methodA(short x){System.out.println("Sub class short method " + x);}
[Code] ....
I've got a question to ask.
public class AutoBoxingExample {
public void add(Integer intVal){
System.out.println("Wrapper");
}
public void add(int value){
System.out.println("Primitive");
}
public static void main(String[] args) {
AutoBoxingExample auto = new AutoBoxingExample();
auto.add(12);
}
}
The output is "Wrapper". What would be the reason behind it?
Why is it necessary to implement the comparable interface for primitive types and not for classes such as Integer, String etc . . . ?
View Replies View RelatedI am totally new to Java. What is the purpose of this method?
Flow of the int x=3; like where does the 3 go step by step?
Passing Primitive Data Type Arguments (from oracle java tutorials)
Primitive arguments, such as an int or a double, are passed into methods by value. This means that any changes to the values of the parameters exist only within the scope of the method. When the method returns, the parameters are gone and any changes to them are lost. Here is an example:
public class PassPrimitiveByValue {
public static void main(String[] args) {
int x = 3;
// invoke passMethod() with
// x as argument
passMethod(x);
[Code] ....
I have doubt in generics,
List<int> c=new ArrayList<int>();
why we cannot use primitive data type like int,double.
I have a code in which I am reading input from System.in and Destination is some where else
Here is my code
File file=new File("D:/output.txt");
OutputStream os=new java.io.FileOutputStream(file);
Scanner scanner=new Scanner(System.in);
System.out.println("Enter Data to write on File");
String text=scanner.nextLine();
int c=Integer.parseInt(text);
int a;
while((a=c.read())!=-1)
os.write(a);
System.out.println("File Written is Successful");
In the line while((a=c.read())!=-1)
a compile time error is shown "cannot invoke read on primitive data type int"
Where I am going wrong?
I have declared an array list that will store data type of 1 Character and 2 integer. The data that will be store in this list is
1. A = {0 3}
2. B = {0 5}
3. C = {0 3}
4. D = {0 3}
5. E = {0 5}
6. F = {0 6}
Now here the alphabets are routers and integers are there con1 and con2 respectively. I have a set of router={ A,B,C,D,E,F}.
Step 1:I have to subtract con1 from con2 i.e. (3-0) of all the routers and
Step 2: then put the router having largest value in new set 1 and
Step 3: then this router will be subtract from the router set.
Step 4:then again I have to repeat the step 1 until the value of routers become <= 1.
Now what I did is I defined 3 arrays first is String array that stores names of routers, 2nd array that stores the first value and 3rd array that stores the second value. I can find the largest value but how to store the name of router against the largest value in the set.
A group of my classmates and I were discussing strings. We were asked, "What circumstances would you want to convert a text string to numerical data?" but we couldn't think of any answers outside of counting characters within the string for various applications.
View Replies View RelatedI need to write a simple program that displays up to 5 pairings of data types (int, string) (string, long) ect. I need to have at least two classes, a Pair class (generic) and an PairTest class.
View Replies View RelatedI have to read data from a text file and print it in a new text file. An example of one line is like this:
Johnson 85 98 75 89 82
I then have to take the average of all the numbers and assign a "grade" to the numbers for each line of the text file and make a new file so it looks like this for 10 lines:
Name 1 2 3 4 5 Average Grade
Johnson 85 98 75 89 82 85.80 B
My problem is extracting the data from the file so I can use it.
I have seen many ways of describing what objects are, one being that objects are a user-defined datatype. However, if objects are datatypes, then what does that make classes? To me, it seems as though classes should be the "types" of data defined by the programmer, and objects should be the specific "values" of that user defined data type. As an example, an integer would be a class, while 1 would be a "value" of that class, i.e. an object. From this point of view, I don't see why a specific number would be a data type... Therefore, why do we say that objects are user defined data types rather than classes?
View Replies View RelatedI am trying to get the excel spreadsheet data and converting it in someway to java. I'm looking for something that will print out the java code itself that way I can embed it into future projects.
View Replies View RelatedI would like to create an ArrayList from data types stored in a text file.The ArrayList would be multidimensional with two data types; int, String.
Example text file could be:
4 cahiers grand format
3 stylots bic bleu
5 gommes
I find it very difficult for multiple data types i don't see how its possible.
I am trying to remove the duplicate elements from ArrayList using .contains() if elements are primitive datatype it works but user-defined datatype does not work.
public class UserBean {
String name;
String address;
public String getName() {
return name;
[code]....
I am creating a calculator in which a user will directly input the numbers and the operator...
Here is my code:
int answer = 0;
int num1, num2;
char operator;
System.out.print("Enter calculation: ");
num1 = kb.nextInt();
operator = kb.next().charAt(0);
num2 = kb.nextInt();
The code above will accept the user input when there are spaces like this: 1 + 1
So the program will give an answer which is 2...BUT
if i input 1+1 it will give an error...Exception in thread "main" java.util.InputMismatchException
How can i do that it will separate integer to character? because i set the operator as character....
So that it will accept one digit to several digit numbers... like 500+84 or 1520+872??
byte a1 = 0;
byte a2 = 4
byte a3 = 4;
//below statement gives a compilation error
a1 = a2 + a3;
//below line compiles fine.
a1 = 4 + 4;
I want to declare integers, while the program is running.
I run the program and then I give it via System.in.println an integer and repeat this as long as I want. I want the program to give those integers a name of a certain type for, for example a(i) or a[i], dunno, (it should be handy) and then a(i) represents the the i'th integer I gave the program. My idea is then that I can use those elements by their name just like, if I had declared them in the first place. For example add two integers together. For example I defined a method add+, which waits for 2 integer and then adds them. For example I write:
add
a(2)
a(47)
(then I would get here the result.)
However I don't know, how to let the program count the number of inputs or how to let it declare and use variables.
How to convert the equation below for bigDecimal objects. I have already tried this, and this and the output is really weird once I call the method. The first block of code is what I'm trying to convert into BigDecimal arithmetic.
public static double calculateFutureValue(double monthlyInvestment,
double monthlyInterestRate, int months) {
double futureValue = 0;
for (int i = 1; i <= months; i++) {
[Code] ....
My attempt at this is as follows:
public static BigDecimal calculateFutureValue(double monthlyInvestment,
double monthlyInterestRate, int months) {
BigDecimal futureValue = new BigDecimal(0.0);
BigDecimal montlyInvestmentDecimal = new BigDecimal(monthlyInvestment);
[Code] ....
Output:
Welcome to the Future Value Calculator
DATA ENTRY
Enter monthly investment: 1
Enter yearly interest rate: .01
Enter number of years: 3
Month: 1 FutureValue: 0E-66
Month: 2 FutureValue: 0E-132
Month: 3 FutureValue: 0E-198
Month: 4 FutureValue: 0E-264
Month: 5 FutureValue: 0E-330
[Code] ....
FORMATTED RESULTS
Monthly investment: $1.00
Yearly interest rate: 0.0%
Number of years: 3
Future value: 0E-2376
Continue? (y/n):
So clearly this still isn't working.
I want to declare integers, while the program is running.
I run the program and then I give it via System.in.println an integer and repeat this as long as I want. I want the program to give those integers a name of a certain type for, for example a(i) or a[i], dunno, (it should be handy) and then a(i) represents the the i'th integer I gave the program. My idea is then that I can use those elements by their name just like, if I had declared them in the first place. For example add two integers together. For example I defined a method add+, which waits for 2 integer and then adds them. For example I write:
add
a(2)
a(47)
(then I would get here the result.)
I don't think implementing the add function is difficult. However I don't know, how to let the program count the number of inputs or how to let it declare and use variables.
This first part of code is my HTML
<!DOCTYPE html>
<html>
<head>
<title>Page Title</title>
<meta charset="UTF-8">
<link href="jquery/jquery.mobile-1.4.5.min.css" rel="stylesheet" type="text/css"/>
<meta name="viewport" content="width=device-width, initial-scale=1">
[Code] .....