Question

i have a code which generates random strings and numbers from random class in C#. and then writes it to a text file. how can i improve the performance?
the code is as follows:

    int i = 0;
    Record[] rec = new Record[100000];
    Class1 cl = new Class1();
    Random random = new Random();
    while (i < 100000)
    {
        rec[i].num1 = random.Next();
        rec[i].num2 = random.Next();
        rec[i].mult = rec[i].num1 * rec[i].num2;
        rec[i].rel = true;
        rec[i].name = cl.generateRandomString(1);
        rec[i].var_set = cl.generateRandomString(2);          
        using (StreamWriter writer = new StreamWriter("important.txt", true))
        {

            writer.Write(rec[i].name);
            writer.Write("   ");
            writer.Write(rec[i].var_set);
            writer.Write("   ");
            writer.Write(rec[i].num1);
            writer.Write("   ");
            writer.Write(rec[i].num2);
            writer.Write("   ");
            writer.Write(rec[i].mult);
            writer.Write("   "); 
            writer.WriteLine(rec[i].rel);
        }
        i++;

Answer 1

what happens when you do this:

Record[] rec = new Record[100000]; 
Class1 cl = new Class1(); 
Random random = new Random(); 
int i = 0;
while (i < 100000) 
{ rec[i].num1 = random.Next(); rec[i].var_set = cl.generateRandomString(2); i++; };

i = 0;
using (StreamWriter writer = new StreamWriter("important.txt", true))
    {

        while ( i < 100000)
        {
        writer.Write(rec[i].name);
        writer.Write("   ");
        writer.Write(rec[i].var_set);
        writer.Write("   ");
        writer.Write(rec[i].num1);
        writer.Write("   ");
        writer.Write(rec[i].num2);
        writer.Write("   ");
        writer.Write(rec[i].mult);
        writer.Write("   "); 
        writer.WriteLine(rec[i].rel);

        i++;
        };
    }

EDIT – another option:

Record[] rec = new Record[100000]; 
Class1 cl = new Class1(); 
Random random = new Random(); 
int i = 0;
while (i < 100000) 
{ rec[i].num1 = random.Next(); rec[i].var_set = cl.generateRandomString(2); i++; };

File.WriteAllLines ( "important.txt", (from r in rec select r.name + "   " + 
r.var_set  + "   " + r.num1 + "   " + r.num2 + "   " + r.mult + 
"   " + r.rel).ToArray());