What is the difference between convert.toint32() int.parse() and casting to int

ToInt32 input11 ; Now, run and see the output. It's successfully converting the give input which contains only number to integer. Let's try converting the integer to integer. ToInt32 input ToString ; Now, run and see the output. Let's try converting the String which contains characters to integer. ToInt32 input33 ; Now, run and see the output.

We know very well, we can not convert the string which contains alphabet to integer, so we are seeing the format exception. Let's try converting Null to integer. ToInt32 input44 ; Now, run and see the output. It's handling null value and returning 0.

ToInt32 input5 ; Now, run and see the output. Let's try converting the String which contains long value to integer. ToInt32 input66 ; Now, run and see the output. Now, we got clear knowledge about Convert.

It's used to convert the input into integer and bool. The input integer should be an integer; if it's null it will return 0; if it's string, it should only contain the number. TryParse int. TryParse input,out is a method to convert the given input into integer, and the tryparse method is always used with out parameter to display default value. Let's have an example to see its unique functionality. TryParse string s, out int result ; Parameter s represents input value, out represents that it's the default value to return while tryparse failed to convert the input as well as the tryparse never fall into the exception because of out param.

Okay, now we move to the examples. First, we will try with converting the boolean to integer. TryParse input ToString , out defaultout ; Console. There is no issue here. It's also converting the bool value to integer. Let's try with converting the string which contains only number to integer. TryParse input, out defaultout ; Console. Let's try with converting the String which contains characters to integer.

ToInt32 takes an object as its argument. See Chris S's answer for how it works. Parse does. That also means that Convert. ToInt32 is probably a wee bit slower than Int Parse , though in practice, unless you're doing a very large number of iterations in a loop, you'll never notice it. No difference as such. ToInt32 calls int. Parse internally. Except for one thing Convert. ToInt32 returns 0 when argument is null.

Parse and Int TryParse can only convert strings. ToInt32 can take any class that implements IConvertible. If you pass it a string, then they are equivalent, except that you get extra overhead for type comparisons, etc.

If you are converting strings, then TryParse is probably the better option. Parse string s method converts the string representation of a number to its bit signed integer equivalent.

When s is a null reference, it will throw ArgumentNullException. If s is other than integer value, it will throw FormatException. For example :. ToInt32 string s method converts the specified string representation of bit signed integer equivalent. This calls in turn Int Parse method. When s is a null reference, it will return 0 rather than throw ArgumentNullException.

The first of these functions, Parse, is one that should be familiar to any. Net developer. This function will take a string and attempt to extract an integer out of it and then return the integer. Also, it can throw an ArgumentException if you pass it a null value. TryParse is a new addition to the new. Net 2. The main difference is that exception handling is very slow, so if TryParse is unable to parse the string it does not throw an exception like Parse does.

Instead, it returns a Boolean indicating if it was able to successfully parse a number. So you have to pass into TryParse both the string to be parsed and an Int32 out parameter to fill in. We will use the profiler to examine the speed difference between TryParse and Parse in both cases where the string can be correctly parsed and in cases where the string cannot be correctly parsed. The Convert class contains a series of functions to convert one base class into another.

I believe that Convert. ToInt32 string just checks for a null string if the string is null it returns zero unlike the Parse then just calls Int Parse string. Source with examples. ToInt32 allows null value, it doesn't throw any errors Int. It depends on the parameter type. Not exactly the functionality I intended Here is a detail for int.

Parse and Convert. The Convert. ToInt32 a[0] will give you a number of Parse a[0] will give you the right output which is 1. ToInt32 and int. Colin Angus Mackay wrote: Why is it better that Convert. There are advantages to having an integer-conversion method that will never throw an exception. I don't see an advantage to having one that throws an exception in every invalid case except when the input parameter is a null reference note that Convert.

ToInt32 will throw an exception on an empty string. Incidentally, at least in Basic there are a couple of other ways of converting numbers: Val and CInt. These are willing to accept more input formats than the other methods, but they have different semantics for conversion.

Too bad there's no "try" version of it. You now appear to be contradicting yourself. You said in the article "Convert. Parse, since it return 0 rather than exception". These are willing to accept more input formats than the other methods But you can also get that out of Int You still have not answered why it is better that no exception is thrown?

I didn't write the original article. There are times when it is best for a failure to return an exception; there are other times when it is better for it not to.

The latter approach is a lot bulkier; worse, it requires that one enumerate all the exceptions one wants to handle. If the some particular input will cause the Parse method to throw an unanticipated exception, the program will die. Catching a generic Exception would avoid that problem, but would run the risk that real exceptions like "out of memory" might go unhandled.

My bad! Re: Some comments David A. You state that catching a generic exception would run the risk of leaving a "real" exception, such as "out of memory" unhandled.

My experience has been otherwise. I have yet to find an exception that falls through a generic System. Exception catch block. Moreover, the exception handler can identify and classify exceptions that derive from System. Exception by their derived type. For example, in my AppExceptionLogger class, there is a private method, ReformatExceptionMessage , which formats specific types of exceptions in ways not supported by their native Message properties. Its first argument is an Exception.

As always, Exception can be either a true System. Exception or an object that derives from System. The second executable statement calls the GetType method on the Exception, and stores the value of the FullName from the returned system. Substring MagicNumbers. IndexOf strTrimStartPoint ; return string.

ReplaceToken strTrimmedMsg , Environment. Parse tries to convert it to an int and stores the answer in the variable result. As str2 is null, it is not possible to perform the conversion. Thus, it gives an ArgumentNullException. Then, the catch block executes, and the exception message is displayed on the screen. Figure 3: Program 3 with int Parse. According to the above program, str3 stores a string. Parse tries to convert it to an int and stores the answer in the result variable.

As the value is a decimal value, it is not possible to perform the conversion. Thus, it gives a FormatException. Therefore, the catch block executes, and the exception message is displayed on the screen. Figure 4: Program 4 with int Parse. According to the above program, str4 stores a string. As the value is too large, it is not possible to perform the conversion.

So, it gives an OverflowException.