difference between Convert.ToInt32 and (int)

Posted by balalakshmi on Stack Overflow See other posts from Stack Overflow or by balalakshmi
Published on 2009-10-22T17:40:45Z Indexed on 2010/03/08 2:12 UTC
Read the original article Hit count: 430

Filed under:

c#

|

type-conversion

the following syntax throws an compile time error like

Cannot convert type 'string' to 'int'

string name=(Session["name1"].ToString());
int i = (int)name;

whereas the code below compiles and executes successfully

string name=(Session["name1"].ToString());
int i = Convert.ToInt32(name);

I would like to know
1) why the compile time error occurs in first code
2) what's the difference between the 2 code snippets

© Stack Overflow or respective owner

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> More

Related posts about type-conversion

General type conversion without risking Exceptions

as seen on Stack Overflow - Search for 'Stack Overflow'
I am working on a control that can take a number of different datatypes (anything that implements IComparable). I need to be able to compare these with another variable passed in. If the main datatype is a DateTime, and I am passed a String, I need to attempt to convert the String to a DateTime… >>> More
javascript arrays and type conversion inconsistencies

as seen on Stack Overflow - Search for 'Stack Overflow'
I have been playing with javascript arrays and I have run into, what I feel, are some inconsistencies, I hope someone can explain them for me. Lets start with this: var myArray = [1, 2, 3, 4, 5]; document.write("Length: " + myArray.length + "<br />"); for( var i in myArray){ document.write(… >>> More
Automatic type conversion in Java?

as seen on Stack Overflow - Search for 'Stack Overflow'
Is there a way to do automatic implicit type conversion in Java? For example, say I have two types, 'FooSet' and 'BarSet' which both are representations of a Set. It is easy to convert between the types, such that I have written two utility methods: /** Given a BarSet, returns a FooSet */ public… >>> More
Explicit Type Conversion and Multiple Simple Type Specifiers

as seen on Stack Overflow - Search for 'Stack Overflow'
To value initialize an object of type T, one would do something along the lines of one of the following: T x = T(); T x((T())); My question concerns types specified by a combination of simple type specifiers, e.g., unsigned int: unsigned int x = unsigned int(); unsigned int x((unsigned int())); Visual… >>> More
Error using traits class.: "expected constructor destructor or type conversion before '&' token"

as seen on Stack Overflow - Search for 'Stack Overflow'
I have a traits class that's used for printing out different character types: template <typename T> class traits { public: static std::basic_ostream<T>& tout; }; template<> std::ostream& traits<char>::tout = std::cout; template<> std::wostream& traits<unsigned… >>> More