How to use the bool data type?-CodePudding

I have in my code the specificacions of the bool to return true or false but I don't figure how to printf depending if it is true or false. I have some float prompted by the user and the bool to determine if it is true or false. How can I use these both datas to printf depending?

bool valid_triangle(float x, float y, float z);
int main(void)
{
    float x;
    float y;
    float z;
    do
    {
        x = get_float("Enter a length: ");
    }
    while(x <= 0);
    do
    {
        y = get_float("Enter other length: ");
    }
    while(y <= 0);
    do
    {
        z = get_float("The last one: ");
    }
    while(z <= 0);
}
if(valid_triangle = 1)
{
    printf("It's a triangle");
}
bool valid_triangle(float x, float y, float z)
{
    if(x <= 0 || y <= 0 || z <= 0)
    {
        return false;
    }
    if((x   y <= z) || (x   z <= y) || (y   z <= x))
    {
        return false;
    }
    return true;
}

I tried an if conditional with the bool but doesn`t compile.

CodePudding user response：

This:

if(valid_triangle = 1)

tries to re-assign the valid_triangle function to the integer 1. That does not compile; the names of functions behave like constants and cannot be assigned to.

You need something like:

if (valid_triangle(x, y, z))
{
  printf("yay, got a valid triangle with sides %f, %f and %f!\n", x, y, z);
}

The above calls the valid_triangle() function, passing it the three values you collected from the user. If the return vale is non-zero (which true is), the if will execute its body, otherwise it will be skipped.

Note that I (strongly) advise against explicit comparisons against booleans, since the comparison operator itself simply results in a boolean value which makes it feel painfully recursive to me. I also don't think it's any clearer.

CodePudding user response：

Your valid_triangle function expects 3 arguments x, y, z. You have to pass the values you take from user to the function.

if(valid_triangle(x, y, z) == true)
{
    printf("It's a triangle");
} else {
    printf("It's not a triangle");

}