Any questions from newcomers on MQL4 and MQL5, help and discussion on algorithms and codes - page 108

[Vitalie Postolache]

-Aleks-:

So, I have such a probe - you can put a line in long, but I need double for calculations with a decimal point.

Well, this seems to work fine.

double CalcY=StringToDouble("0.01234567890001");
Print ("CalcY=",DoubleToString(CalcY,14));

2017.02.05 23:52:50.190 00 EURUSD,M1: CalcY=0.01234567890001

[Aleksey Vyazmikin]

Vitalie Postolache:

This seems to work fine.

double CalcY=StringToDouble("0.01234567890001");
Print ("CalcY=",DoubleToString(CalcY,14));

I have 18 digits in a number.

[Vitalie Postolache]

-Aleks-:

I have 18 digits in a number.

Who has it easy nowadays...

Text output is only up to 16 characters, it's written in black and white in the documentation. And the calculations are up to the limit of the data type.

[Aleksey Vyazmikin]

Vitalie Postolache:

Who has it easy nowadays...

Text output is only up to 16 characters, it's written in black and white in the documentation. And calculations - up to the limit provided by the data type.

So I'm talking about calculation - number is just fine without preforming into string. But the double calculation itself with a number is limited, as I understand it, to 15 digits. Or is it 15 digits in both directions - before the decimal point and after?

DBL_MIN	Minimum positive value which can be represented by double	2.2250738585072014e-308
DBL_MAX	Maximum value which can be represented by double type	1.7976931348623158e+308
DBL_EPSILON	The smallest number for which the condition 1.0+DBL_EPSILON != 1.0 is met	2.2204460492503131e-016
DBL_DIG	Number of significant decimal places	15
DBL_MANT_DIG	Number of bits in mantissa	53
DBL_MAX_10_EXP	Maximum decimal value of exponent degree	308
DBL_MAX_EXP	Maximum binary value of exponent degree	1024
DBL_MIN_10_EXP	Minimum Decimal Value of exponent degree	(-307)
DBL_MIN_EXP	Minimum binary value of exponent degree	(-1021)

[Aleksey Vyazmikin]

-Aleks-:

I understand that the double with a number is limited to 15 digits. Or is it 15 digits in both directions - before and after the decimal point?

The limit is a maximum of 15 digits, so the comma is irrelevant.

[Maksym Mudrakov]

int Counter (int type, string sy, enum counterEnum{TIME_1_SY, TOTAL, LOCK})
{
...
}

Please advise, I want to declare an enumeration in function parameters, so that only the following values can be selected as the third parameter when the function is called:
TIME_1_SY, TOTAL or LOCK

How to implement this?

I figured it out, it turned out to be very simple:

enum CE {TIME_1_SY, TOTAL, LOCK};
int Counter (int type, string sy, int counterEnum)
{
...
}

[vivatforex]

Hello, could you please tell me the code for this program

if(ObjectFind("Rectangle 33579")==0) Alert("YES");
else Alert("NO");

It signals several times "YES" then several times "NO" if the object exists and all the time "NO" if the object doesn't, but why such a simaphore when the object exists?

[Artyom Trishkin]

Maksym Mudrakov:

int Counter (int type, string sy, enum counterEnum{TIME_1_SY, TOTAL, LOCK})
{
...
}

Please advise, I want to declare an enumeration in function parameters, so that only the following values can be selected as the third parameter when the function is called:
TIME_1_SY, TOTAL or LOCK

How to implement this?

Declare an enumeration in the global scope. And use the enumeration as a parameter type in the function.

[Vitaly Muzichenko]

vivatforex:

Hello, could you tell me please, here is the code of the program

if (ObjectFind("Rectangle 33579")==0) Alert("YES");
else Alert("NO");

It signals several times "YES" then several times "NO" if the object exists and all the time "NO" if the object does not exist, but why such a simaphore when the object exists?

Try it like this:

if (ObjectFind(0,"Rectangle 33579")<0) Alert("НЕТ");
else Alert("ДА");

[Mickey Moose]

Hi all.

Who can see why it displays like this?

I.e. the functions are different properties but the display is the same.

Also with two other objects of the same type, only one of them works, other parameters are ignored