# finding the power to a number then the user inputs a max a min power

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• 11-19-2011, 11:35 PM
vicu1
finding the power to a number then the user inputs a max a min power
hi guys ineed some help on a basic program. the user has to input a base and a min and max of powers. from there the program has to determine all the answers including the min and max and has to output them. example: base: 2 min: 1 max: 3 so the answer should be
2 4 8. i have started the code but i dont know where to go from here:
Code:

```package numberssquared; import TerminalIO.KeyboardReader; public class Square {     public static void main(String[] args) {           KeyboardReader reader = new KeyboardReader();           int base;           int minnumber;           int maxnumber;           double squarenumber = 0;           int number;                 base = reader.readInt("what is the base: ");           minnumber = reader.readInt("what is the first exponent ");           maxnumber =  reader.readInt("what is the second exponent: ");               for(number = minnumber; number <= maxnumber; number ++)                     squarenumber = Math.pow(base, number);               System.out.print(squarenumber);                   } // end main() }  // end class```
this will just display the last power so for that exmaple it just answers 8. the for stament does work and when i tested it, it said 1 2 3 which is right. but it doesnt work when its enterd into the math.pow.
• 11-20-2011, 12:49 AM
Norm
Re: finding the power to a number then the user inputs a max a min power
Check the formatting of your code. It is very important that you align the ending } vertically beneath the start of the statement with the beginning {. Statements within {} should be indented 3-4 spaces.

If you properly indent and align your code you will see what the problem is.
• 11-20-2011, 12:59 AM
vicu1
Re: finding the power to a number then the user inputs a max a min power
umm i dont understand what u are saying. is it a simple } mistake becuase i checked it and there are suppose to be two at the end. but should the loop first terminate and then after that should i write the math.pow statement?
• 11-20-2011, 01:41 AM
Norm
Re: finding the power to a number then the user inputs a max a min power
What do you want your code to print out? Can you copy the command prompt console from when you execute the program and post it here? Add comments to it describing what is wrong with the output and show what you want the output to be.
To copy the contents of the command prompt window:
Click on Icon in upper left corner
Select Edit
Select 'Select All' - The selection will show
Click in upper left again
Select Edit and click 'Copy'

Paste here.
• 11-20-2011, 01:48 AM
pbrockway2
move along, nothing to see here
Glad to see everyone at the forum today!
• 11-20-2011, 01:53 AM
Norm
Re: finding the power to a number then the user inputs a max a min power
Thanks. I bet my wife someone would tell the OP what his problem was instead of telling him how to find his problem. So now I don't have to pay.
• 11-20-2011, 01:59 AM
pbrockway2
Re: finding the power to a number then the user inputs a max a min power
Whoops, sorry. I didn't read your first post properly. Knee jerked, fingers typed.
• 11-20-2011, 02:01 AM
Norm
Re: finding the power to a number then the user inputs a max a min power
We'll see if the OP is awake.
• 11-20-2011, 03:18 AM
vicu1
Re: finding the power to a number then the user inputs a max a min power
ok well i have given you my code. here is a test run that i did:
what is the base: 3
what is the first exponent 2
what is the second exponent: 4
81.0
so this is saying that 3^4 is that number. however i also want it to say what 3^2 is and what 3^3 is.
do you understand what i mean?
• 11-20-2011, 06:48 AM
pbrockway2
Re: finding the power to a number then the user inputs a max a min power
So that "System.out.print(squarenumber)" is only happening once.

Did you do what Norm suggested in #2 and indent everything between { and }? (and nothing else) What did the code look like when you did that?
• 11-20-2011, 05:56 PM
vicu1
Re: finding the power to a number then the user inputs a max a min power
um i am a little confused. didnt i indent it when i posted my code?
• 11-20-2011, 05:58 PM
Norm
Re: finding the power to a number then the user inputs a max a min power
Not correctly. See my post#2.
I have since formatted it according to my standards.
• 11-20-2011, 06:00 PM
Norm
Re: finding the power to a number then the user inputs a max a min power
Add a println to print the value of number immediately after the for statement and see what prints out. It will show you how many times the loop goes around.
• 11-20-2011, 06:28 PM
vicu1
Re: finding the power to a number then the user inputs a max a min power
yes i did that before i posted this: what is the base: 2
what is the first exponent 3
what is the second exponent: 5
3
4
5
64.0
i understand that the for statement works but why doesnt the math.pow read only the last number entered?
• 11-20-2011, 06:31 PM
Norm
Re: finding the power to a number then the user inputs a max a min power
Quote:

why doesnt the math.pow read only the last number entered
Add a println that prints the values of base and number just before where you call math.pow to show how many times math.pow is being called.
• 11-20-2011, 08:32 PM
vicu1
Re: finding the power to a number then the user inputs a max a min power
ok so i did that:

Code:

```    for(number = minnumber; number <= maxnumber; number ++)             System.out.println(base);             System.out.println(number);             squarenumber = Math.pow(base,number);             System.out.print(squarenumber);```
what is the base: 2
what is the first exponent 3
what is the second exponent: 4
2
2
5
32.0
i dont understand what is happening. i didnt do anything to the base in the for statement.
• 11-20-2011, 08:34 PM
Norm
Re: finding the power to a number then the user inputs a max a min power
Why do you have lines 3, 4 and 5 indented? Do you think indenting them will put them in the for loop?
• 11-20-2011, 08:39 PM
vicu1
Re: finding the power to a number then the user inputs a max a min power
ok so do you mean i have to write another for statement? i feel like that is what i have to do. my teacher i think said there shpuld be a lot of for statements. But how would i start it? would it be something like for(squarenumber = Math.pow(base,number).......
• 11-20-2011, 08:50 PM
Norm
Re: finding the power to a number then the user inputs a max a min power
No, one for statement should do it.

Why do you have the statements on lines 3, 4 and 5 indented? Do you think indenting them will put them in the for loop?
If those statements are outside of the for loop then they should start in the same column as the for.
Here is the correct formatting for your code. There is one statement in the for loop. The other 3 are outside.
Code:

```    for(number = minnumber; number <= maxnumber; number ++)             System.out.println(base);     System.out.println(number);     squarenumber = Math.pow(base,number);     System.out.print(squarenumber);```
• 11-20-2011, 08:54 PM
JosAH
Re: finding the power to a number then the user inputs a max a min power
Java is not Python; in Python both <statement1> and <statement2> are executed each time the body of the for loop is executed:

Code:

```for(number = minnumber; number <= maxnumber; number ++)   <statement1>   <statement2>```
Not so in Java; white space and indentation means nothing to Java. In Java the above could've been writen as:

Code:

```for(number = minnumber; number <= maxnumber; number ++)   <statement1> <statement2>```
Only <statement1> makes up the body of the for loop; if you want both statements to be part of the for loop, you have to use curly brackets:

Code:

```for(number = minnumber; number <= maxnumber; number ++) {   <statement1>   <statement2> }```
Again, space mean nothing to Java, you could've written this instead (as long as the curly brackets are there):

Code:

```for(number = minnumber; number <= maxnumber; number ++) { <statement1> <statement2> }```
kind regards,

Jos
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