QueryCAT Logo
Search 5,000,000+ questions and answers.

Frequently Asked Questions

How can I convert from string to int ?

C++ corner
You want to make a function that converts from a type to another. Like from std::string to int, or the other way around. This can be done using std::stringstream and insertion / extraction operators. Just as above, templates will prove of great help: Its usage is not as straightforward as the above explained max template. Normally, you would want to call it like "int value = lexical_cast( myStdString );". There is, however, a problem.

How do I convert a string to an int etc?

FAQ for the microsoft.public.languages.csharp newsgroup
In general, when you want to convert from one type to another, the first class to look at is System.Convert. It has a load of static methods which are likely to help you. If you're converting from a String, you could also check whether the type that you want to convert to has a Parse method or something similar - for instance, I usually use DateTime.ParseExact to convert from a String to a DateTime.

Sect. 18) How do I convert a String to an int?

Java Programmer's FAQ - Part D
There are several ways. The most straightforward is: String myString = numString.trim(); int i = Integer.parseInt(myString); long l = Long.parseLong(myString) or String myString = numString.trim(); i = Integer.parseInt(myString,myIntRadix); Note 1: There is a gotcha with parseInt - it will throw a NumberFormatException for String values in the range "80000000" to "ffffffff". You might expect it to interpret them as negative, but it does not. The values have to be "-80000000" .

Sect. 18) How do I convert an int to a string?

Java Programmer's FAQ - Part D
Try any of these: String s = String.valueOf(i); or String s = Integer.toString(i); or String s = Integer.toString(i, radix); or // briefer but may result in extra object allocation. String s = "" + i; Note: There are similar classes for Double, Float, Long, etc.

How to convert an int to a char array or C++ string?

Tech Talk about C++ and C Issues / Comeau C++ and C FAQ
How to add a float (or "any" type really) to the end of a C++ string? Unlike routines like atoi mentioned in the previous question, there is no direct routine such as itoa available. However, similar to the string I/O routines in the previous question, one can do this: #include <stdio.h> // cstdio in C++ // ..

How do I convert a string to a double or int? What plays the role of atof and atoi in C#?

Windows Forms FAQ - Windows Forms from MFC
You use static members of the Convert class found in the System namespace to handle conversions in the .NET framework.

How can I convert an INT into CHAR*/STRING or vice versa?

Beginner FAQ - GPWiki
This is something you do a lot in programming and pretty much every language makes it easy to convert between types. You may have already printed integers to the console with COUT or PRINTF, which of course needs to be converted to a string first. Converting numbers to strings is done in a similar way. Boost is a C++ library that can help you with problems like these and many others.

How do I convert a string to a number?

Updating the For Beginners forum FAQ - GameDev.Net Discussio...
I am including the header file <string>, and I am using the string class, but the code doesn't compile? (namespace resolution, having the std:: topics) How do I use unique() with vectors? (answered only once, but still a good question to have due to people not knowing that it's possible to do)

How to convert the datetime into a string for use in the SQL ' statement?

Megasolutions.net :: Asp.Net Frequently Asked Questions - FA...
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Private Sub ddlCulture_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ddlCulture.SelectedIndexChanged

How do I convert an integer to a string representation?

CSC 209 Summer 2006
Well, printf does it for output, so look at its related function named sprintf that "prints formated output to a string."

How can I convert an integer or a float to a string?

Frequently Asked Questions
It's easy. Use sprintf. For example: char string1[50]; char string2[50]; short int var1; float var2; ... sprintf (string1, "%d", var1); sprintf (string2, "%f", var2);

How do I convert a std::string to a number?

Miscellaneous technical issues, C++ FAQ Lite
There are two easy ways to do this: you can use the <cstdio> facilities or the <iostream> library. In general, you should prefer the <iostream> library.

How do I convert a string into an internet address?

Programming UNIX Sockets in C - Frequently Asked Questions: ...
If you are reading a host's address from the command line, you may not know if you have an aaa.bbb.ccc.ddd style address, or a host.domain.com style address. What I do with these, is first try to use it as a aaa.bbb.ccc.ddd type address, and if that fails, then do a name lookup on it. Here is an example: Converts ascii text to in_addr struct. NULL is returned if the address can not be found.

How do I read a String/int/boolean/etc from the keyboard?

Java Programmer's FAQ
The easiest way is to pick up the source for the 100% pure Java class EasyIn from http://www.afu.com/ (same place as this FAQ) Compile it with your code and use it like this: EasyIn easy = new EasyIn(); int i = easy.readInt(); // gets an int from System.in boolean b = easy.readBoolean(); // gets a boolean from System.in double d = easy.readDouble(); // gets a double from System.in ... etc.

How can I show an int as a binary number - a string of 1s and 0s?

FAQ for the microsoft.public.languages.csharp newsgroup
The Convert class has an overload of the static ToString() method that takes two ints and returns a string populated with the number in the specified base. For instance, calling Convert.ToString(128, 2) will return "10000000".

Can QEngine script support string/int variable?

AdventNet QEngine - Frequently Asked Questions
Yes, QEngine supports string/int variables usage in the script. This will help you to use the business logics of your application to validate the results shown in your pages. For e.g., you can define a variable like below variableA=25 variableB=”Use this string” You can also cast a string variable to int for using it in a loop structure or somewhere else like below. variableA=”25” // int value stored as a string variable.

Can QEngine support to manipulate any string / int data inside the script?

AdventNet QEngine - Frequently Asked Questions
Yes, you can manipulate any string/int data inside the script. You can use + - * / for int value manipulations. For string manipulation QEngine provides you many functions like Java

In a call to malloc, what does an error like ''Cannot convert 'void *' to 'int *''' mean?

Memory Allocation
It's never necessary to multiply by sizeof(char), since sizeof(char) is, by definition, exactly 1. (On the other hand, multiplying by sizeof(char) doesn't hurt, and in some circumstances may help by introducing a size_t into the expression; see question 7.15.) See also questions 8.9 and 8.10. I wrote a little wrapper around malloc, but it doesn't work: #include <stdio.h> #include <stdlib.

Explore Other Topics

How long does it take to install a new furnace or air conditioner?
How do I install Windows XP on an SATA hard drive?
I lost my voter registration card. Do I need it to vote? How do I get a new one?
How do I read the checking account number and bank routing number on my check?
How efficient are solar panels? How much energy can they produce per square foot?
What are the minimum system requirements for installing the software?
Do we need to have a passport and a birth certificate to get married?
Can I purchase a garage door opener only at Costco.com?
How far above the roof does the vent pipe need to extend?
Q. What is the difference between Granite and Marble?
When does the Statutory Declarations Act 1835 require a statutory declaration to be used?
What are the disadvantages of Windows Server?
More Questions >>

© Copyright 2007-2009 QueryCAT
About • Webmasters • Contact