When the int variable is more than 10 digits-CodePudding

When the int variable is more than 10 digits, an error occurs and the number becomes negative.

Why is this happening and how can I solve the problem?

This is my code:

UnityWebRequest www = new UnityWebRequest("https://api.hypixel.net/skyblock/bazaar");
www.downloadHandler = new DownloadHandlerBuffer();
yield return www.SendWebRequest();
JSONNode itemsData = JSON.Parse(www.downloadHandler.text);
unixtimeOnline = itemsData2["lastUpdated"];
Debug.Log(unixtimeOnline);
    // output -2147483648

CodePudding user response：

tl;dr

Simply use ulong instead of int for unixtimeOnline

ulong unixtimeOnline = itemsData2["lastUpdated"];

What happened?

As was already mentioned int (or also System.Int32) has 32 bits.

The int.MaxValue is

2147483647

no int can be higher than that. What you get is basically a byte overflow.

From the JSON.Parse I suspect you are using SimpleJson

and if you have

int unixtimeOnline = itemsData2["lastUpdated"];

it will implicitly use

public static implicit operator int(JSONNode d)
{
    return (d == null) ? 0 : d.AsInt;
}

which uses AsInt

 public virtual int AsInt
 {
     get { return (int)AsDouble; }
     set { AsDouble = value; }
 }

which is a problem because a double can hold up to

so when you simply do

double d = 2147483648.0;
int example = (int)d;

you will again get

-2147483648

What you want

You want to use a type that supports larger numbers. Like e.g.

long: goes up to
```
9,223,372,036,854,775,807
```
and is actually what system time ticks are usually stored as (see e.g. DateTime.Ticks

or actually since your time is probably never negative anyway directly use the unsigned ones

ulong: goes up to
```
18,446,744,073,709,551,615
```

Solution

Long store short: There are implicit conversion for the other numeric values so all you need to do is use

ulong unixtimeOnline = itemsData2["lastUpdated"];

and it will use AsUlong instead

public static implicit operator ulong(JSONNode d)
{
    return (d == null) ? 0 : d.AsULong;
}

which now correctly uses

 public virtual ulong AsULong
 {
     get
     {
         ulong val = 0;
         if (ulong.TryParse(Value, out val))
             return val;
         return 0;
     }
     set
     {
         Value = value.ToString();
     }
 }

CodePudding user response：

As the comment says you will need to use a long variable type