Float to string

why this doest work?
error: float cannot be dereferenced
System.out.println(Float.parseFloat(3.0).toString())
can any expert tell me?
thx
your
terry

System.out.println(Float.parseFloat(3.0).toString())Not an expert but the parseFloat returns a native which doesn't have a toString method. I would use the other post that creates a new Float() object. Or just take the toString() off and it should work. Natives print just fine. Like in...
int z = 123;
String x = "Hello, my tag is " + z + "#";
// x will print "Hello, my tag is 123#";

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I want to extract float from string (%f %s) or (%s %f) separated by tab, whitespace etc., Since I am using jdk1.3.1 I can't use regular expression can anybody suggest a simple (one or two or few line code - compact) to get the float in (sign+/-)#.#### format ignoring other characters ?
I tried:
e.g.,
String d="4.000 [tab]4";
source string resulted from "SUBSTRING query of mySQL" can be of :
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6.580
6.000
If String containing data separated by comma:
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AAXXFE     ,4.206     1     ,
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===
String pattern = "###.###";
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String output = myFormatter.format(d);
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===

Hi
You made the best choice. JRegex is closer to java.util.regex.* and fine works with excellent performance in any JVM version so you can use examples/tutorials from both JRegex and Java.Sun.Com to learn more about regular expression.
About the regular expression in my last post, there are two capturing groups: the first for float numbers in IEEE format specification (also see Java Language Specification) and the second for any sequence of chars, groups using with any amount of blank spaces (spaces, tabs, etc :: see regular expression definition) as delimiter. The anchors "^" and "$" are being used to exactly match pattern in target string and you can relax this constraint as needed.
How to use JRegex? no secrets!
import jregex.*;
// a float number and string with any blank delimiter
String patternString ="^([+-]?(?:\\d+(?:\\.\\d*)?|\\.\\d+)(?:[eE][+-]?\\d+)?)\s+(.*)$";
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// below is identical in both packages
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Float to string conversion

import java.lang.String;
import java.lang.Integer;
import java.lang.Float;
import java.util.Hashtable;
import java.util.Enumeration;
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public VenkatCart() {
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public Enumeration getEnumeration() {
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String tmpItem[];
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String tmpItem[];
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When I call the method "getCost()" from a jsp program, I get the error message
Error: java.lang.Float: method parseFloat(Ljava/lang/String;)F not found has been reported.
I think the mistake is in conversion.
Please help me.
My thanks in advance.

Why don't you try the following:
Float tmpFloat=new Float(tmpItem[3]);
totalCost += (Integer.parseInt(tmpItem[4]) * tmpFloat.floatValue();
Justyna

Float to string conversion (E-\d)

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Try java.text.DecimallFormat:
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I created a small program that converts currency for the iPhone. Unfortauntely, I cannot get the UILabel to display my float value. Apparently, NS can though. I found a tutorial that told me simply to use this:
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Message was edited by: hollafortwodollas

Simple requirements:
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I have a decimal string "122339994" which i am trying to convert to float using Float.parseFloat. This results in incorrect value of 1.22339992E8.
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String floatString = "122339994";
float floatNumber = Float.parseFloat(floatString);
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See this API
[Java2SE Float|http://download-llnw.oracle.com/javase/6/docs/api/java/lang/Float.html#valueOf%28java.lang.String%29]
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"1.00000017881393421514957253748434595763683319091796875001d"
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If you take time to read it would ne better...and you can help efficiently...
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hi
try this
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data : a type f,
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write :/ a.
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may be it can be!!!
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� {�

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I need to assign a float value from a database to a variable recurrently throughout a while loop. but i am getting a null pointer exception error:
while ( rs.next() )
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Null pointer exception means that the value you are trying to turn into a Float is null. Probably request.getParameter("echo") returns null.
Is "echo" a request parameter, or a field you want to get from the database?
request.getParameter() has nothing to do with a database query.
That is your http request coming from the form submission. It won't change.
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If its a database field (stored as a number) then
float corr = rs.getFloat("echo");
should do the trick.
Can the value be null in the database?
Cheers,
evnafets

How to search for particular string in array?

I am struggling to figure out how to search array contents for a string and then delete the entry from the array if it is found.
The code for a program that allows the user to enter up to 20 inventory items (tools) is posted below; I apologize in advance for it as I am also not having much success grasping the concept of OOP and I am certain it is does not conform although it all compiles.
Anyway, if you can provide some assistance as to how to go about searching the array I would be most grateful. Many thanks in advance..
// ==========================================================
// Tool class
// Reads user input from keyboard and writes to text file a list of entered
// inventory items (tools)
// ==========================================================
import java.io.*;
import java.text.DecimalFormat;
public class Tool
private String name;
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int units;
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 price = costPrice;
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 boolean valid;
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 BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
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 valid = false;
 try
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 itemQty = stdin.readLine();
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 qty = Integer.parseInt (itemQty);
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 while (!valid);
 do
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 try
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 System.out.print(" Enter item #" + recordNum + " cost (A$) > ");
 itemCost = stdin.readLine();
 // Parse float as string
 price = Double.parseDouble(itemCost);
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 dataFile.println(fmt.format(price));
 valid = true;
 catch(NumberFormatException exception)
 // Throw error for all non-number input (integers
 // allowed)
 System.out.println();
 System.out.println(" Only numbers please. Try again.");
 while (!valid);
 // Prompt to add another item
 System.out.println();
 System.out.print(" Add another item? Y/N > ");
 addItem = stdin.readLine();
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 System.out.println();
 System.out.println(" Not a valid option. Try again.");
 System.out.print(" Add another item? Y/N > ");
 addItem = stdin.readLine();
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 // Increment record number by 1
 recordNum++;
 if (addItem.equalsIgnoreCase("N"))
 System.out.println();
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 System.out.println();
 System.out.println(" Quitting program.");
 while (addItem.equalsIgnoreCase("Y"));
// Close input file
dataFile.close();
 if (choice == 2)
 try {
 Read user input (array search string)
 Search array
 If match found, remove entry from array
 Confirm "deletion" and display new array contents
 catch block {
} // class
// ==========================================================
// ListToolDetails class
// Reads a text file into an array and displays contents as an inventory list
// ==========================================================
import java.io.*;
import java.util.StringTokenizer;
import java.text.DecimalFormat;
public class ListToolDetails {
 // Declare variable
 private Tool[] toolArray; // Reference to an array of objects of type Tool
 private int toolCount;
 public static void main(String args[]) throws Exception {
 String line, name, file = "test.txt";
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 double price, total = 0;
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 final int MAX = 20;
 Tool[] items = new Tool[MAX];
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 System.out.println();
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 + "PRICE" + "\t" + "TOTAL");
 System.out.println("\t" + "\t" + "\t" + "\t" + "PRICE");
 System.out.println();
 try {
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 FileReader fr = new FileReader(file);
 BufferedReader inFile = new BufferedReader(fr);
 StringTokenizer tokenizer;
 while ((line = inFile.readLine()) != null) {
 tokenizer = new StringTokenizer(line, "\t");
 name = tokenizer.nextToken();
 try {
 units = Integer.parseInt(tokenizer.nextToken());
 price = Double.parseDouble(tokenizer.nextToken());
 items[count++] = new Tool(name, units, price);
 total = units * price;
 } catch (NumberFormatException exception) {
 System.out.println("Error in input. Line ignored:");
 System.out.println(line);
 System.out.print(" " + count + "\t");
 System.out.print(line + "\t");
 System.out.print(fmt.format(total));
 System.out.println();
 inFile.close();
 } catch (FileNotFoundException exception) {
 System.out.println("The file " + file + " was not found.");
 } catch (IOException exception) {
 System.out.println(exception);
 System.out.println();
 // Unfinished functionality for displaying "error" message if user tries to
 // add more than 20 tools to inventory
 public void addTool(Tool maxtools) {
 if (toolCount < toolArray.length) {
 toolArray[toolCount] = maxtools;
 toolCount += 1;
 } else {
 System.out.print("Inventory is full. Cannot add new tools.");
 // This should search inventory by string and remove/overwrite matching
 // entry with null
 public Tool getTool(int index) {
 if (index < toolCount) {
 return toolArray[index];
 } else {
 System.out
 .println("That tool does not exist at this index location.");
 return null;
} // classData file contents:
TOOL 1 1 1.21
TOOL 2 8 3.85
TOOL 3 35 6.92

Ok, so you have an array of Strings. And if the string you are searching for is in the array, you need to remove it from the array.
Is that right?
Can you use an ArrayList<String> instead of a String[ ]?
To find it, you would just do:
for (String item : myArray){
 if (item.equals(searchString){
 // remove the element. Not trivial for arrays, very easy for ArrayList
}Heck, with an arraylist you might be able to do the following:
arrayList.remove(arrayList.indexOf(searchString));[edit]
the above assumes you are using 1.5
uses generics and for each loop
[edit2]
and kinda won't work it you have to use an array since you will need the array index to be able to remove it. See the previous post for that, then set the value in that array index to null.
Message was edited by:
BaltimoreJohn

How do I convert a string into a decimal

I've been tryin to convert a string into decimal but I can't get it to work at all. I keep getting an exception.
I've tried all of these:
double myDouble = Double.valueOf(string).doubleValue();
int myint = Interger.parseInt(string);
float myfloat = Float.parseFloat(string);
I can't get anything to work.
That string i'm reading in is an array containing values with decimals. ex: -45.09348
All the above work fine if there is no decimal, but fails when it comes to one.
How do I go about doing this?
Thanks!

This works for me:String s = "-45.6789";
double d = Double.parseDouble(s);
System.out.println(d);Mark

Double.parseDouble(String) - problems when string is in scientific notation

Hello guys,
I'm doing some numerical calculations and I wonder whether it is possible for Double.parseDouble(String) to parse string in the scientific notation i.e. 1.0824234234E-10. Is it the notation itself causing the exception : NumberFormatException or the number is just too big/small and double can't hold it ?
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Regards

i'm not quite sure whether double odoes not allow it.
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if (Pattern.matches(fpRegex, myString))
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http://java.sun.com/j2se/1.5.0/docs/api/java/lang/Double.html

Display Large Float w/o Scientific Notation

I have a series of dollar amounts (from an SQL cursor) that I am summing up using a java.lang.Float. The values total correctly, but when I display the value it is displayed using Scientific Notation (4.19150150185925 E12). I need to write my total value to a file that will be exported to another application (mainframe). Therefore, the value when written to the output file must be 4191501501859.25. How do I get the value in that form, instead of the scientific notation form?
Should I be using a different type to sum my values into? The max value my total can reach is 99999999999999999.999
Thanks.

No, I meant precisely what I said. If BigDecimal
does indeed have a valueOf method that accepts a
string, please notify Sun, as they will certainly
have to update the documentation -- didn't YOU
read the documentation link that you yourself
sent me?
No, of course not, I only checked that it indeed does not have any method that takes a String parameter and that the method to "add" numbers is really called "add".
By the way, a constructor that takes a String parameter does pretty much the same thing as a method that takes a String parameter and returns a new instance of the class. There is no significant difference between Float's valueOf(String) and the Float(String) constructor as far the user of the API is concerned.
(Looking up the source just for fun I see that Float.valueOf(String) and Float(String) do completely different things, and Float(String) creates a temporary extra Float object. The comment above says: "REMIND: this is inefficient". Interesting.)
Probably not, you were apparently too busy taking
a 'tude.No doubt! :-)

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