CODEWITHSUNDEEP
javastringnumbers
nmagerko
nmagerko

Reputation: 6794

Number Manipulation from Strings

I am trying to figure out how to do two things :

  1. Change a number from a String to a double and back to a String.
  2. How to manipulate different parts of a double.

To explain :

In the first case, I would like the user to be able to input a number into the a JTextArea so I can store the input in a variable (simple). Then, I would like to perform operations on the number that is inputted, but this cannot be done with a string. Is there any way to convert input into a double?

Then, I would like to take this string, after it has been converted into a double, and analyze the specific digits, and the digits of its decimal places (tenths, hundredths, etc.) as well using if-else and for statements (I can do this part). My understanding of strings is that, if I say NameofString[0], I will get the first letter of the string, but can this be done with a Number?

Lastly, I would like to convert this double back into a String.

Upvotes: 0

Views: 832

Answers (3)

BillRobertson42
BillRobertson42

Reputation: 12883

Also, NameofString[0] will not work in Java. but you can call myString.charAt(0) though. To your question about extracting digits from a double would either require conversion to a string or doing some math on the number to pull digits out.

Upvotes: 1

COD3BOY
COD3BOY

Reputation: 12102

The translation part is discussed in the answer by @Howard, Now for analyzing specific digits, I suppose you need to use the / and % judiciously.

say for example, 

while(x!>0)
{
  x%10    // will return the digit at the tenths position.

   Now,

  x=x/10  //will give you the remaining part.

}

Upvotes: 1

Howard
Howard

Reputation: 39197

You can parse a string using (assuming x is a double variable and s a string)

x = Double.parseDouble(s);

and convert the number back to a string via

s = Double.toString(x);

If you want to format the value according to a specific format you may want to use String.format instead.

Upvotes: 5

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