conversion double to float

donaldk · #1 11-Feb-2006, 07:10

warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(261) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(270) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(280) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(28

: warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(29

: warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(304) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data

I need help badly. I can compile my program but is warning have stop me from get the program to run well. Can someone guide me along and what possible error do i have. thanks

cable_guy_67 · #2 11-Feb-2006, 07:14

Hello and Welcome to GIDForums™ donaldk. Please read the Sticky that gives some good guidelines for posting. Without any code, it is not likely you will get much help.

Mark

davekw7x · #3 11-Feb-2006, 08:17

Quote:

Originally Posted by donaldk

warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
e:\ap power\project4.cpp(261) : warning C4244: '=' : conversion from 'double' to 'float', possible loss of data
warning have stop me from get the program to run well.

These are warnings, not errors. Look at the lines that were flagged. Was there some assignment to a variable of type float? Was there a function call where a parameter was of type float? What?

Since "doubles" have more precision than "floats", assignment of an expression that has type "double" to a variable or function parameter that has type "float" will give this message with (some) C++ compilers. Note that floating point literals, such as 3.3 are treated by compilers as "doubles". If you want to make sure the compiler treates it as a "float", then use 3.3f in expressions.

No one can here tell you whether the items flagged by these messages cause your program not to "run well", since no one here has seen your code. In fact, we don't have any way of knowing what you mean by not running well. What exactly happens when you attempt to run your program?

You might get rid of the messages by changing your variables from "floats" to "doubles" (if the program specification allows that). If you have variables, x and y of type "float", and you have something like x = y / 3.0;, you could either change the declarations of x and y to make them "doubles" or you could change the assgnment statement to x = y / 3.0f.

Regards,

Dave

donaldk · #4 12-Feb-2006, 22:16

Hi, thanks for the guiding and help. However, i need to help to analysis the program of the car parking. This program allow user to key in "Entry point X to the car park and Exit point A or Exit point B from the car park.It also allow user the key in the entry time and exit time.
It is the charges of the park slots that confuse me. I need help in analysis the last past of the function.

void amount(struct transaction inf[],int h)

For peak hours, 7am to 5.59pm, the parking charge for the car parking is $1.00 per half-hour. For non-peak hours, 6pm to 6.59am, the parking charge is $0.50 per half-hour. The parking is always calculated to the nearest half-hour
Below is the program.

CPP / C++ / C Code:

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<ctype.h>
#define MAX 5

struct vehicle{
	int vehi_no;
	float timein;
};
struct transaction{
	struct vehicle data;
	char exit_point[1];
	float timeout;
	float amount;
};
void toupperC(char *con);
int entry(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*i);
int outA(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*waitb);
int outB(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*waitb);
void amount(struct transaction inf[],int h);
void vehiF(struct transaction inf[],int j);
void printfile(struct transaction inf[],int h);
main()
{
	printf("The carpark is empty at initial.\n");
	int a,b,c,d,e;   //carlot status
	a=b=c=d=e=0;
	int waita,waitb;	//condition of whether car is waiting.
	waita=waitb=0;
	int i,j; //num of carlots free.
	i=0;
	int num;
	char condition[20];
	struct transaction info[MAX+5];
	while(i!=100000)  //for ever loop.
	{
  		if(waita==1 && waitb==1)
		{
			waita=waitb=0;
			printf("There is a vancant carlot,pls proceed.\n");
			j=entry(info,&a,&b,&c,&d,&e,&i);
			vehiF(info,j);
		}
		printf("Please enter car in or out : ");
		fflush(stdin);
		gets(condition);
		toupperC(condition);
		if(strcmp(condition,"ENTRY POINT X")==0)
		{
			if(i==5)
			{
				printf("Carpark is full.pls wait\n\n");
				waita=1;
			}
			else
			{
				j=entry(info,&a,&b,&c,&d,&e,&i);
				vehiF(info,j);
			}
		}
		else if((strcmp(condition,"EXIT POINT A")==0) || (strcmp(condition,"EXIT POINT B")==0))
		{
			if(i==0)
			{
				printf("There is no car in the carpark.\nPlease don't play a fool.\n\n");
			}
			else if(strcmp(condition,"EXIT POINT A")==0)
			{
				i=i-1;
				num=outA(info,&a,&b,&c,&d,&e,&waitb);
				amount(info,num);
				printfile(info,num);
			}
			else if(strcmp(condition,"EXIT POINT B")==0)
			{
				i=i-1;
				num=outB(info,&a,&b,&c,&d,&e,&waitb);
				amount(info,num);
				printfile(info,num);
			}
		}
		else
			printf("Invalid Input.\nPlease enter again.\n\n");
	}
	return 0;
}
void toupperC(char *con)
{
	char *ptr;
	ptr=con;
	while(*ptr !='\0')
	{
		if(isalpha(*ptr))
		{
			*ptr=toupper(*ptr);
			ptr++;
		}
		else
			ptr++;
	}
	return;
}
int entry(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*i)
{
	int f=0;

	if(*a==0)
	{
		*a=1;
		f=0;
	}
	else if(*b==0)
	{
		*b=1;
		f=1;
	}
	else if(*c==0)
	{
		*c=1;
		f=2;

	}
	else if(*d==0)
	{
		*d=1;
		f=3;
	}
	else if(*e==0)
	{
		*e=1;
		f=4;
	}
	(*i)++;
	printf("Please enter the 4-digit vehicle number : ");
	scanf("%d",&inf[f].data.vehi_no);
	//fflush(stdin);
	//gets(inf[f].data.vehi_no);
	printf("Please enter time of entry in '24.00' hr format : ");
	scanf("%f",&inf[f].data.timein);
	printf("Time enter into carpark is %.2f\n",inf[f].data.timein);
	printf("Please proceed to carlot number %d.\n",f+1);
	printf("The Barrier is lifted.\n");
	printf("The Barrier is closed.\n\n");
	return f;
}
int outA(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*waitb)
{
	*waitb=1;
	int E;
	int z=5;
	printf("Please enter your 4-digit vehicle number : ");
	scanf("%d",&E);
	while(z==5)
	{
		z=0;
		while(inf[z].data.vehi_no!=E)
		{
			z++;
			if(z>4)
			{
				z=0;
				printf("No such car.\n");
				printf("Please enter your 4-digit vehicle number again : ");
				scanf("%d",&E);
			}
		}
	}
	printf("Please enter time of exit in 24.00 hr : ");
	scanf("%f",&inf[z].timeout);
	strcpy(inf[z].exit_point,"A");
	printf("The Barrier at exit A is lifted.\n");

	switch(z)
	{
	case 0:*a=0;break;
	case 1:*b=0;break;
	case 2:*c=0;break;
	case 3:*d=0;break;
	case 4:*e=0;break;
	}
	return z;
}
int outB(struct transaction inf[],int *a,int *b,int *c,int *d,int *e,int
*waitb)
{
	*waitb=1;
	int E;
	int z=5;
	printf("Please enter your 4-digit vehicle number : ");
	scanf("%d",&E);
	while(z==5)
	{
		z=0;
		while(inf[z].data.vehi_no!=E)
		{
			z++;
			if(z>4)
			{
				z=0;
				printf("No such car.\n");
				printf("Please enter your 4-digit vehicle number again : ");
				scanf("%d",&E);
			}
		}
	}
	printf("Please enter time of exit in 24.00 hr : ");
	scanf("%f",&inf[z].timeout);
	strcpy(inf[z].exit_point,"B");
	printf("The Barrier at exit B is lifted.\n");
	switch(z)
	{
	case 0:*a=0;break;
	case 1:*b=0;break;
	case 2:*c=0;break;
	case 3:*d=0;break;
	case 4:*e=0;break;
	}
	return z;
}
[b][color="Red"]void amount(struct transaction inf[],int h)
{
	float g,l;
	float S1,S2,S3,S4,S5,T;
	S1=S2=S3=S4=S5=T=0;
	g=inf[h].data.timein;
	l=inf[h].timeout;
	if(0<g && g<6.59)
	{
		if(0<l && l<6.59)  // is check corrected.
		{
			if(l>g)
			{
				while((l-g)>=1)
				{
					l=l-1;
					S1++;
				}
				while(l>=1)
				{
					l--;
				}
				while(g>=1)
				{
					g--;
				}
				if(g>l)
				{
					g=0.59-g+l;
					while(g>0)
					{
						g=g-0.3;
						S3++;
					}
				}
				else
				{
					l=l-g;
					while(l>0)
					{
						l=l-0.3;
						S3++;
					}
				}
				T=S1+(S3/2);
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
			else
			{
				g=6.59-g;
				while(g>=1)
				{
					g--;
					S1++;
				}
				while(g>0.3)
				{
					g=g-0.3;
					S2++;
				}
				while(l>=1)
				{
					l--;
					S3++;
				}
				while(g>0.3)
				{
					l=l-0.3;
					S4++;
				}
				g=g+l;
				while(g>0)
				{
					g=g-0.3;
					S5++;
				}
				T=28+S1+S3+(S2+S4+S5)/2;
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
		}
		else if(7<l && l<17.59)  //is check corrected.
		{
			g=6.59-g;
			while(g>=1)
			{
				g--;
				S1++;
			}
			while(g>0)
			{
				g=g-0.3;
				S2++;
			}
			l=l-7;
			while(l>=1)
			{
				l--;
				S3++;
			}
			while(l>0)
			{
				l=l-0.3;
				S4++;
			}
			T=S1 + (S2/2) + (S3*2) + S4;
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
		else if(18<l && l<23.59)  //is checked correct.
		{
			g=6.59-g;
			while(g>1)
			{
				g--;
				S1++;
			}
			while(g>0.3)
			{
				g=g-0.3;
				S2++;
			}
			l=l-18;
			while(l>=1)
			{
				S3++;
				l--;
			}
			while(l>0.3)
			{
				S4++;
				l=l-0.3;
			}
			g=g+l;
			while(g>0)
			{
				g=g-0.3;
				S5++;
			}
			T=S1+S3+(S2+S4+S5)/2+22;
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
	}
	else if(7<g && g<17.59)
	{
		if(0<l && l<6.59)  //is checked correct.
		{
			g=17.59-g;
			while(g>=1)
			{
				S1++;
				g--;
			}
			while(g>0)
			{
				g=g-0.3;
				S2++;
			}
			while(l>=1)
			{
				S3++;
				l--;
			}
			while(l>0)
			{
				S4++;
				l=l-0.3;
			}
			T=6+(S1*2)+S2+S3+(S4/2);
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
		else if(7<l && l<17.59)  //also corrected.
		{
			if(l>g)
			{
				while((l-g)>=1)
				{
					l=l-1;
					S1++;
				}
				while(l>=1)
				{
					l--;
				}
				while(g>=1)
				{
					g--;
				}
				if(g>l)
				{
					g=0.59-g+l;
					while(g>0)
					{
						g=g-0.3;
						S2++;
					}
				}
				else
				{
					l=l-g;
					while(l>0)
					{
						l=l-0.3;
						S2++;
					}
				}
				T=(S1*2)+S2;
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
			else
			{
				g=17.59-g;
				while(g>1)
				{
					g--;
					S1++;
				}
				while(g>0.3)
				{
					g=g-0.3;
					S2++;
				}
				l=l-7;
				while(l>=1)
				{
					l--;
					S3++;
				}
				while(l>=0.3)
				{
					l=l-0.3;
					S4++;
				}
				g=g+l;
				while(g>0)
				{
					g=g-0.3;
					S5++;
				}
				T=13+(S1+S3)*2+S2+S4+S5;
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
		}
		else if(18<l && l<23.59)  // is corrected.
		{
			g=17.59-g;
			while(g>1)
			{
				g--;
				S1++;
			}
			while(g>0)
			{
				g=g-0.3;
				S2++;
			}
			l=l-18;
			while(l>=1)
			{
				l--;
				S3++;
			}
			while(l>0)
			{
				l=l-0.3;
				S4++;
			}
			T=(S1*2)+S2+S3+(S4/2);
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
	}
	else if(18<g && g<23.59)
	{
		if(0<l && l<6.59)
		{
			g=23.59-g;
			while(g>1)
			{
				g--;
				S1++;
			}
			while(g>0.3)
			{
				g=g-0.3;
				S2++;
			}
			while(l>=1)
			{
				l--;
				S3++;
			}
			while(l>0.3)
			{
				l=l-0.3;
				S4++;
			}
			g=g+l;
			while(g>0)
			{
				g=g-0.3;
				S5++;
			}
			T=S1+S3+((S4+S2+S5)/2);
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
		else if(7<l && l<17.59)
		{
			g=23.59-g;
			while(g>1)
			{
				g--;
				S1++;
			}
			while(g>0)
			{
				g=g-0.3;
				S2++;
			}
			l=l-7;
			while(l>=1)
			{
				l--;
				S3++;
			}
			while(l>0)
			{
				l=l-0.3;
				S4++;
			}
			T=7+S1+S3*2+S4+S2/2;
			inf[h].amount=T;
			printf("Please pay $%.2f\n\n",inf[h].amount);
		}
		else if(18<l && l<23,59)
		{
			if(l>g)
			{
				while((l-g)>=1)
				{
					l=l-1;
					S1++;
				}
				while(l>1)
				{
					l--;
				}
				while(g>1)
				{
					g--;
				}
				if(g>l)
				{
					g=0.59-g+l;
					while(g>0)
					{
						g=g-0.3;
						S2++;
					}
				}
				else
				{
					l=l-g;
					while(l>0)
					{
						l=l-0.3;
						S2++;
					}
				}
				T=S1+(S2/2);
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
			else
			{
				g=23.59-g;
				while(g>1)
				{
					g--;
					S1++;
				}
				while(g>0.3)
				{
					g=g-0.3;
					S2++;
				}
				l=l-18;
				while(l>=1)
				{
					l--;
					S3++;
				}
				while(l>0.3)
				{
					S4++;
					l=l-0.3;
				}
				g=g+l;
				while(g>0)
				{
					g=g-0.3;
					S5++;
				}
				T=29+S1+S3+(S2+S4+S5)/2;
				inf[h].amount=T;
				printf("Please pay $%.2f\n\n",inf[h].amount);
			}
		}
		return;
	}
}[/color][/b]void vehiF(struct transaction inf[],int j)
{
	FILE *fout;
	fout=fopen("Vehicle.txt","a");
	if(fout==NULL)
	{
		printf("Error reading file.");
		exit(1);
	}
	fprintf(fout,"Vehicle number = %d\nTime entry is %.2f\n\n",inf[j].data.vehi_no,inf[j].data.timein);
	fclose(fout);
	return;
}
void printfile(struct transaction inf[],int h)
{
	FILE *fout;
	fout=fopen("Transaction.txt","a");
	if(fout==NULL)
	{
		printf("Error reading file.");
		exit(1);
	}
	fprintf(fout,"Vehicle number = %d\nTime entry is %.2f\nTime exit is %.2f\nAmount charged is %.2f\nExited from exit %s\n\n",inf[h].data.vehi_no,inf[h].data.timein,inf[h].timeout,inf[h].amount,inf[h].exit_point);
	fclose(fout);
	inf[h].data.vehi_no=987654;
	return;
}

davekw7x · #5 12-Feb-2006, 22:46

Quote:

Originally Posted by donaldk

Hi, thanks for the guiding and help. However, i need to help to analysis the program of the car parking.
Below is the program.

Let's see; by my rough approximation, there are about 668 lines of code and about 416 are highlighted in red.

I think there is a typographical error on line 566:

CPP / C++ / C Code:

		else if(18<l && l<23,59)

Probably should be 23.59, not 23,59

Regards,

Dave

Guidelines Plz · #6 12-Feb-2006, 23:16

Quote:

Originally Posted by davekw7x

Let's see; by my rough approximation, there are roughly 668 lines of code and about 416 are highlighted in red.

And after being asked to read the Guidelines, too. Maybe you should reread them, esp #1 and #2. #3 wouldn't hurt either.

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