How do i convert Strings to Integers?

Question

So just got into programming. Hopefully this can help me to explain: String age = ; Console.WriteLine(Enter age:); age = Console.ReadLine(); Now i want to take that age and convert it to an integer so as i can manipulate it to work out the users age in Months weeks days hours minutes and seconds. As i recall you can do this with a Console. command and i remember the command having a '32' in it somewhere any help would be appreciated. New to this site also hoping it will help me through college as the course consists of using C#. :) -Stuart

Vulpes · Answer

You can do it either like this: int iAge = Convert.ToInt32(age); or like this: int iAge = int.Parse(age); Also if you want to avoid throwing an exception if the user enters something which can't be parsed to an integer you can do this: int iAge; bool isValid = int.TryParse(age out iAge); If 'age' can be parsed to an integer then isValid will be true and iAge will contain the result. If 'age' cannot be parsed to an integer then isValid will be false and iAge will contain the default value of 0. Also if you want to allow a fractional age to be input then just replace int or Int32 with double or Double: double dAge = Convert.ToDouble(age); or: double dAge = double.Parse(age); or: double dAge; bool isValid = double.TryParse(age out dAge);

Carl Cioffi · Answer

You could take that 1 step further with the following: int iAge = 61; int yearofbirth = DateTime.Now.Year - iAge ; DateTime x = new DateTime(yearofbirth); TimeSpan xx = DateTime.Now.Subtract(x); The TimeSpan object with give you almost all of that information with doing all of those calculations and will be more accurate taking into considerations the correct number of days in each year.

Stuart Cowen · Answer

Of course thanks! that would explain the large numbers i was getting! thanks

Vulpes · Answer

Oops just noticed a mistake in your code namely that when working out the number of weeks you don't want to multiply by 12 first. So it should be: Console.WriteLine(You are  + (iage * 12) +  months old); Console.WriteLine(You are  + (iage * 52) +  weeks old); Console.WriteLine(You are  + (iage * 52 * 7) +  days old); Console.WriteLine(You are  + (iage * 52 * 7 * 24) +  hours old); Console.WriteLine(You are  + (iage * 52 * 7 * 24 * 60) +  minutes old); Console.WriteLine(You are  + (iage * 52 * 7 * 24 * 60 * 60) +  seconds old); There's also a slight inaccuracy in that 52 * 7 = 364 whereas years will of course have either 365 or 366 days though that's probably unimportant in the context of what you're doing. You're still going to exceed the maximum value of an Int32 (2147483647) for people you are 69 or over. To avoid that you could define iAge to be long (or Int64) which has a much larger range.

Stuart Cowen · Answer

Haha yes And actually you need to use BigIntegers i believe else sometimes the result for seconds comes out as minus numbers and all sorts

Vulpes · Answer

Looks good to me though the number of seconds old is a bit frightening :)

Stuart Cowen · Answer

Thanks a bunch it was the Convert.ToInt32(age); I was confusing the Convert with Console. Thanks though much help for a beginner such as myself! However i can see int.Parse(age); being much more easy to remember. Just to say - this is what I've come up with String name = ; String age = ; int end = 0; while (end == 0) { Console.WriteLine(Enter name:); name = Console.ReadLine(); Console.WriteLine(Enter Age:); age = Console.ReadLine(); int iage; bool isValid = int.TryParse(age out iage); if (iage != 0) { Console.WriteLine(Hello  + name + .); Console.WriteLine(You are  + iage +  years old); Console.WriteLine(You are  + (iage * 12) +  months old); Console.WriteLine(You are  + (iage * 12 * 52) +  weeks old); Console.WriteLine(You are  + (iage * 12 * 52 * 7) +  days old); Console.WriteLine(You are  + (iage * 12 * 52 * 7 * 24) +  hours old); Console.WriteLine(You are  + (iage * 12 * 52 * 7 * 24 * 60) +  minutes old); Console.WriteLine(You are  + (iage * 12 * 52 * 7 * 24 * 60 * 60) +  seconds old); end = 1; } else { Console.WriteLine(Please enter an integer e.g.) 9); } } Console.WriteLine(Press enter to exit.); Console.ReadLine();