What is the maximum value for an int32?

Answer 1

What do you mean? It should be easy enough to remember that it is 2^32. If you want a rule to memorize the value of that number, a handy rule of thumb is for converting between binary and decimal in general:

2^10 ~ 1000

which means 2^20 ~ 1,000,000

and 2^30 ~ 1,000,000,000

Double that (2^31) is rounghly 2 billion, and doubling that again (2^32) is 4 billion.

It's an easy way to get a rough estimate of any binary number. 10 zeroes in binary becomes 3 zeroes in decimal.

Answer 2

Int32 means you have 32 bits available to store your number. The highest bit is the sign-bit, this indicates if the number is positive or negative. So you have 2^31 bits for positive and negative numbers.

With zero being a positive number you get the logical range of (mentioned before)

+2147483647 to -2147483648

If you think that is to small, use Int64:

+9223372036854775807 to -9223372036854775808

And why the hell you want to remember this number? To use in your code? You should always use Int32.MaxValue or Int32.MinValue in your code since these are static values (within the .net core) and thus faster in use than creating a new int with code.

My statement: if know this number by memory.. you're just showing off!

Answer 3

if you can remember the entire Pi number, then the number you are looking for is at the position 1,867,996,680 till 1,867,996,689 of the decimal digits of Pi

The numeric string 2147483647 appears at the 1,867,996,680 decimal digit of Pi. 3.14......86181221809936452346214748364710527835665425671614...

source: http://www.subidiom.com/pi/

Answer 4

If you happen to know your ASCII table off by heart and not MaxInt :
!GH6G = 21 47 48 36 47

Answer 5

Well, aside from jokes, if you're really looking for a useful memory rule, there is one that I always use for remembering big numbers.

You need to break down your number into parts from 3-4 digits and remember them visually using projection on your cell phone keyboard. It's easier to show on a picture:

As you can see, from now on you just have to remember 3 shapes, 2 of them looks like a Tetris L and one looks like a tick. Which is definitely much easier than memorizing a 10-digit number.

When you need to recall the number just recall the shapes, imagine/look on a phone keyboard and project the shapes on it. Perhaps initially you'll have to look at the keyboard but after just a bit of practice, you'll remember that numbers are going from top-left to bottom-right so you will be able to simply imagine it in your head.

Just make sure you remember the direction of shapes and the number of digits in each shape (for instance, in 2147483647 example we have a 4-digit Tetris L and a 3-digit L).

You can use this technique to easily remember any important numbers (for instance, I remembered my 16-digit credit card number etc.).

Answer 6

In Objective-C (iOS & OSX), just remember these macros:

#define INT8_MAX         127
#define INT16_MAX        32767
#define INT32_MAX        2147483647
#define INT64_MAX        9223372036854775807LL

#define UINT8_MAX         255
#define UINT16_MAX        65535
#define UINT32_MAX        4294967295U
#define UINT64_MAX        18446744073709551615ULL