nested loop

[evantri]

i tried to do this nested loop function

double minx = -1.0
double maxx = 1.0
double miny = -1.0
double maxy = 1.0
double x;
double y;

for (x=minx;x<=maxx ;x+0.5)
{
for (y=miny;y<=maxy ;y+0.5)
{
z = x*y;
}
}
printf(value of z is %.10lf\n",z);


but after compiling the program it does nothing. could someone help me why the program does not print out the value of z here?

[vermarajeev]

Your for loop is incorrect. It goes to infinte.
Put somthing like this

for (x=minx;x<=maxx;x = x+0.5)
{
   for (y=miny;y<=maxy;y = y+0.5)
    {
       z = x*y;
    }
}

[Banfa]

Yes or

for (x=minx;x<=maxx;x+=0.5)
{
    for (y=miny;y<=maxy;y+=0.5)
    {
        z = x*y;
    }
}

Additionally you have

left out ; at the end of the lines declaring minx, maxx, miny and maxy
not declared z
missed a " out og your printf statement


Note you will only get 1 line of output since the printf statement is not in any for loop;

[bitong]

Question:

Isn't it that if you declare double you use %e instead of %f? just asking =)

i tried to do this nested loop function

double minx = -1.0
double maxx = 1.0
double miny = -1.0
double maxy = 1.0
double x;
double y;

for (x=minx;x<=maxx ;x+0.5)
{
for (y=miny;y<=maxy ;y+0.5)
{
z = x*y;
}
}
printf(value of z is %.10lf\n",z);


but after compiling the program it does nothing. could someone help me why the program does not print out the value of z here?

[Banfa]

Question:

Isn't it that if you declare double you use %e instead of %f? just asking =)

You are correct, %lf actually refers to a type of long double (80 bits on some machines).

Interestingly though, in scanf I have delt with numerous problems on here recently where the cause seemed to be if you give scanf %f then it expects pointer to float. I thought than scanf and printf basically took the same format strings but floating point values seem to be a situation where they differ.

I think that this may be because floats are automatically promoted to doubles in a function call where as points remain exactly what they are.