What is the maximum value for an int32?

Answer 1

Rather than think of it as one big number, try breaking it down and looking for associated ideas eg:

• 2 maximum snooker breaks (a maximum break is 147)
• 4 years (48 months)
• 3 years (36 months)
• 4 years (48 months)

The above applies to the biggest negative number; positive is that minus one.

Maybe the above breakdown will be no more memorable for you (it's hardly exciting is it!), but hopefully you can come up with some ideas that are!

Answer 2

Largest negative (32bit) value : -2147483648
(1 << 31)

Largest positive (32bit) value : 2147483647
~(1 << 31)

Mnemonic: "drunk AKA horny"

drunk ========= Drinking age is 21
AK ============ AK 47
A ============= 4 (A and 4 look the same)
horny ========= internet rule 34 (if it exists, there's 18+ material of it) 

21 47 4(years) 3(years) 4(years)
21 47 48       36       48

Answer 3

Remember this: 21 IQ ITEM 47

It can be de-encoded with any phone pad, or you can just write one down yourself on a paper.

In order to remember "21 IQ ITEM 47", I would go with "Hitman:Codename 47 had 21 missions, which were each IQ ITEM's by themselves".

Or "I clean teeth at 21:47 every day, because I have high IQ and don't like items in my mouth".

Answer 4

Here's a mnemonic for remembering 2**31, subtract one to get the maximum integer value.

a=1,b=2,c=3,d=4,e=5,f=6,g=7,h=8,i=9

Boys And Dogs Go Duck Hunting, Come Friday Ducks Hide
2    1   4    7  4    8        3    6      4     8

I've used the powers of two up to 18 often enough to remember them, but even I haven't bothered memorizing 2**31. It's too easy to calculate as needed or use a constant, or estimate as 2G.

Answer 5

The easiest way to remember is to look at std::numeric_limits< int >::max()

For example (from MSDN),

// numeric_limits_max.cpp

#include <iostream>
#include <limits>

using namespace std;

int main() {
   cout << "The maximum value for type float is:  "
        << numeric_limits<float>::max( )
        << endl;
   cout << "The maximum value for type double is:  "
        << numeric_limits<double>::max( )
        << endl;
   cout << "The maximum value for type int is:  "
        << numeric_limits<int>::max( )
        << endl;
   cout << "The maximum value for type short int is:  "
        << numeric_limits<short int>::max( )
        << endl;
}

Answer 6

Assuming .NET -

Console.WriteLine(Int32.MaxValue);