C#•3y ago

Why all my randoms are the same? [Answered]

so there is the code and the outputs why are they the same and how to change it?

28 Replies

private static double GetRandomNumber(double minimum, double maximum)
        {
            Random random = new();
            return random.NextDouble() * (maximum - minimum) + minimum;
        }

private static double GetRandomNumber(double minimum, double maximum)
        {
            Random random = new();
            return random.NextDouble() * (maximum - minimum) + minimum;
        }

        public static void CreateInstance()
        {
            string strSeperator = ";";
            StringBuilder sbOutput = new();
            _ = new Random();

            double x = SharedClass.RarityLvlValue.Rarity * 0.4;

            for (var i = 1; i <= 5; i++)
            {
                RarityBonus["button" + i] = new RarityStats(
                    armorPen:       Math.Round(GetRandomNumber(12, 22), 1) * x,
                    hitRate:        Math.Round(GetRandomNumber(100, 250), 1) * x,
                    basicDmg:       Math.Round(GetRandomNumber(300, 900), 1) * x,
                    critChance:     Math.Round(GetRandomNumber(4, 11), 1) * x,
                    stunChance:     Math.Round(GetRandomNumber(1, 4), 1) * x,
                    elementalDmg:   Math.Round(GetRandomNumber(150, 900), 1) * x,
                    dmg:            Math.Round(GetRandomNumber(8, 18), 1) * x,
                    highMonster:    Math.Round(GetRandomNumber(17, 29), 1) * x,
                    lowMonster:     Math.Round(GetRandomNumber(14, 32), 1) * x);
            } 
            sbOutput.AppendLine(string.Join(strSeperator, RarityBonus));
            File.AppendAllText(@"C:\Users\Admin\Desktop\WiT\Semestr 4\Solutions\SimulatorApk\dictRarity.txt", sbOutput.ToString());
        }

        public static void CreateInstance()
        {
            string strSeperator = ";";
            StringBuilder sbOutput = new();
            _ = new Random();

            double x = SharedClass.RarityLvlValue.Rarity * 0.4;

            for (var i = 1; i <= 5; i++)
            {
                RarityBonus["button" + i] = new RarityStats(
                    armorPen:       Math.Round(GetRandomNumber(12, 22), 1) * x,
                    hitRate:        Math.Round(GetRandomNumber(100, 250), 1) * x,
                    basicDmg:       Math.Round(GetRandomNumber(300, 900), 1) * x,
                    critChance:     Math.Round(GetRandomNumber(4, 11), 1) * x,
                    stunChance:     Math.Round(GetRandomNumber(1, 4), 1) * x,
                    elementalDmg:   Math.Round(GetRandomNumber(150, 900), 1) * x,
                    dmg:            Math.Round(GetRandomNumber(8, 18), 1) * x,
                    highMonster:    Math.Round(GetRandomNumber(17, 29), 1) * x,
                    lowMonster:     Math.Round(GetRandomNumber(14, 32), 1) * x);
            } 
            sbOutput.AppendLine(string.Join(strSeperator, RarityBonus));
            File.AppendAllText(@"C:\Users\Admin\Desktop\WiT\Semestr 4\Solutions\SimulatorApk\dictRarity.txt", sbOutput.ToString());
        }

the output

[button1,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button2,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button3,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button4,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button5,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12]

[button1,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button2,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button3,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button4,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12];

[button5,  ArmorPenetration: 38.72
 BonusHitRate 322.56
 BonusBasicDmg: 969.92
 BonusCritChance: 12.8
 StunChance: 3.2
 ElementalDmg: 492.16
 BonusDmg: 25.92
 HighLvlMonsterDmg: 54.72
 LowLvlMonsterDmg: 45.12]

why am i not getting "new" random for every instance?

Kesa•3y ago

you are, it's just that it's happening so fast that the seed ends up being the same because you are creating a new Random every time. consider keeping around the Random instance and just re-using it instead of newing it up every time.

Susko3•3y ago

make a static Random and use that instead of creating a new one also, due to Math.Round you're not getting an even distribution of values

pox•3y ago

Random.Shared

WhiteboyOP•3y ago

winforms .net framework 4.7.2

TheRanger•3y ago

yeah that doesnt happen in .Net core

WhiteboyOP•3y ago

@TheRanger i have other similar class but on ints not doubles and works just fine

TheRanger•3y ago

it seems Random in .Net Framework gives the same seed

WhiteboyOP•3y ago

[button1,  Dmg: 232 - 814
 HitRate: 102
 CritChance: 13
 CritDmg: 304
 Rarity: 1
 Upgrade Lvl: 0];

[button2,  Dmg: 562 - 1942
 HitRate: 425
 CritChance: 8
 CritDmg: 356
 Rarity: 7
 Upgrade Lvl: 0];

[button3,  Dmg: 1380 - 1989
 HitRate: 1001
 CritChance: 11
 CritDmg: 437
 Rarity: 0
 Upgrade Lvl: 0];

[button4,  Dmg: 1751 - 2259
 HitRate: 893
 CritChance: 16
 CritDmg: 423
 Rarity: 3
 Upgrade Lvl: 0];

[button5,  Dmg: 2405 - 3041
 HitRate: 554
 CritChance: 11
 CritDmg: 273
 Rarity: 6
 Upgrade Lvl: 0]

[button1,  Dmg: 232 - 814
 HitRate: 102
 CritChance: 13
 CritDmg: 304
 Rarity: 1
 Upgrade Lvl: 0];

[button2,  Dmg: 562 - 1942
 HitRate: 425
 CritChance: 8
 CritDmg: 356
 Rarity: 7
 Upgrade Lvl: 0];

[button3,  Dmg: 1380 - 1989
 HitRate: 1001
 CritChance: 11
 CritDmg: 437
 Rarity: 0
 Upgrade Lvl: 0];

[button4,  Dmg: 1751 - 2259
 HitRate: 893
 CritChance: 16
 CritDmg: 423
 Rarity: 3
 Upgrade Lvl: 0];

[button5,  Dmg: 2405 - 3041
 HitRate: 554
 CritChance: 11
 CritDmg: 273
 Rarity: 6
 Upgrade Lvl: 0]

TheRanger•3y ago

happens the same with ints but was probably not called so fast which is why you get different numbers

WhiteboyOP•3y ago

so how do i make static random?

TheRanger•3y ago

the same way you define a static method

WhiteboyOP•3y ago

i can't get it to work

mtreit•3y ago

Show your attempt

WhiteboyOP•3y ago

@mtreit i don't know at all

mtreit•3y ago

What part is not clear?

WhiteboyOP•3y ago

@mtreit this

mtreit•3y ago

"this" ?

WhiteboyOP•3y ago

make a static Random and use that instead of creating a new one

mtreit•3y ago

Do you know what static means?

WhiteboyOP•3y ago

private static Random Random()
        {
            Random random = new();
            return random;
        }

private static Random Random()
        {
            Random random = new();
            return random;
        }

sth like this? i get that there are static members but making a static random?

mtreit•3y ago

No, make it a static field instead of a method

WhiteboyOP•3y ago

so like Random random = 0.5?

mtreit•3y ago

Then have each method that needs random numbers access that field or take the Random instance as a method parameter and pass the static field as a parameter static Random _random = new Random(); As a field of your class that contains the methods Be aware that Random isn't thread safe though

WhiteboyOP•3y ago

what does that mean D:

mtreit•3y ago

It means if you are writing multi-threaded code you need to be careful and avoid concurrent access to instances of Random. If you aren't writing multi-threaded / concurrent code right now, don't worry about it.

WhiteboyOP•3y ago

okay thank you, now it works

Accord•3y ago

✅ This post has been marked as answered!

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Why all my randoms are the same? [Answered]