Convert.ToInt32(x) the same as (int)x

Question

If x is a value then are the following just syntactically different but effectively the same? Is the second a shortcut for the first?

Convert.ToInt32(x);
(int)x;

Or can one be used in some circumstances over and above the other?

Looking in MSDN it seems that the first is doing something different to the second.

You have the answer still on SO if you search http://stackoverflow.com/questions/3168704/when-to-use-a-cast-or-convert — Dumitrescu Bogdan, Aug 30 '12 at 07:29
And what's the difference between `int.Parse(x)` and `Convert.ToInt32(x)` ? Are they Identical? — Mahdi Tahsildari, Aug 30 '12 at 07:50

Habib · Accepted Answer · 2012-08-30T07:37:34.693

(int) is explicit cast where Convert.ToInt is method

Consider:

string x = "1";
int temp = 0;
temp = Convert.ToInt32(x);
temp = (int)x; //This will give compiler error

Casting works for compatible types:

long l = 123;
int temp2 = (int)l;

double d = 123.2d;
int temp3 = (int)d; // holds only the int part 123

You may see Explicit cast - MSDN

if a conversion cannot be made without a risk of losing information, the compiler requires that you perform an explicit conversion, which is called a cast. A cast is a way of explicitly informing the compiler that you intend to make the conversion and that you are aware that data loss might occur.

thanks for the help `Convert.ToInt` looks pretty useful – whytheq Aug 30 '12 at 16:48 — whytheq, Aug 30 '12 at 16:48

score 2 · Answer 2 · edited Mar 19 '13 at 20:36

2

In addition to all the other posts here, that Convert.ToInt32 tends to round result, whilst int, truncates it.

Example:

  float x = -0.6f;
  var b = Convert.ToInt32(x);
  var r = (int)x;

The result of this is that b==-1, bur r==0.

This is fundamental difference to remember

edited Mar 19 '13 at 20:36

winwaed

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answered Aug 30 '12 at 07:33

Tigran

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score 1 · Answer 3 · answered Aug 30 '12 at 07:29

1

If x is a string containing a number, the first one will succeed but the second one will fail.

object x = "1";
Convert.ToInt32(x); // works
(int)x; // fails

answered Aug 30 '12 at 07:29

Daniel Hilgarth

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score 1 · Answer 4 · answered Aug 30 '12 at 07:29

1

Convert.ToInt32 is a method, which converts many types of objects to int, and (int) is simple casting - which may lead to exceptions

answered Aug 30 '12 at 07:29

JleruOHeP

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score 1 · Answer 5 · answered Aug 30 '12 at 07:30

1

They are different. int is a casting, ToInt32 is a conversion process. It does much more, is more tolerant of incorrect data, and pretty much always works.

answered Aug 30 '12 at 07:30

Jordan

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score 1 · Answer 6 · answered Aug 30 '12 at 07:32

1

For (int)x , built into the CLR and requires that x be a numeric variable otherwise will give an exception.

Convert.ToInt32 is designed to be a general conversion function which convert from any primitive type to a int.

answered Aug 30 '12 at 07:32

Vishal Suthar

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Convert.ToInt32(x) the same as (int)x

6 Answers6