将正整数加到int会使它变成负数

Question

my issue is that when I am adding only positive numbers to an integer it can sometimes become negative. I know that the numbers that are added to the integer are never positive as I have tried putting them in

maths.abs()

My code is below and i would really appreciate some help

int Total = 0;
int First = 0;
int Second = 10000;   
while (First <= Second)
{
    Total += 5000 + (250 * First);
    Console.WriteLine(Total);
    First++;
}
Console.ReadKey();

Answer 1

Please read Checked and Unchecked (C# Reference) . You can opt in to bounds checking on arithmetic operations. EG:

int Total = 0;
int First = 0;
int Second = 10000;

while (First <= Second)
{
    checked
    {
        Total += 5000 + (250 * First);
    }

    Console.WriteLine(Total);
    First++;
}
Console.ReadKey();

Answer 2

As mentioned by others, your int can't take that number and overflows. Using an Int64 instead does what you want.

Int64 Total = 0;
int First = 0;
int Second = 10000;   
while (First <= Second)
{
    Total += 5000 + (250 * First);
    Console.WriteLine(Total);
    First++;
}
Console.ReadKey();

Answer 3

2,147,483,647 is the limit of the integer, you are adding 1 to the "First" integer each iteration of the loop and overflowing the Total integer

1 run = 5000 + 0
2 run = 5000 + 5000 + 250
...
10000 run 12,548,750,000

The integer can't hold that and overflows.

The limit of a int64 is 9,223,372,036,854,775,807. This would work for your code