Question about MQL4 If-statements

[TraderTogami]

If I have a statement like this: 

if(Bool1() || Bool2()){...}

where Bool1 returns True and Bool2 produces an error; does this if-statement produce an error or does Bool2() get ignored. In other words, are if-statements eagerly evaluated in the MQL4 Language?

[Keith Watford]

TraderTogami:

If I have a statement like this: 

if(Bool1() || Bool2()){...}

where Bool1 returns True and Bool2 produces an error; does this if-statement produce an error or does Bool2() get ignored. In other words, are if-statements eagerly evaluated in the MQL4 Language?

I understand that if the first condition is true, the 2nd will not be checked as there is no need to.

Why would Bool2 produce an error?  A bool function should only return true or false.

[TraderTogami]

Keith Watford #:

I understand that if the first condition is true, the 2nd will not be checked as there is no need to.

Why would Bool2 produce an error?  A bool function should only return true or false.

Thanks, and to answer your question, Bool2 can produce an error just like any other function. Example: 

bool Bool2(){

int x = 1/0;

int y = 2; 

return x == y;

}

[Keith Watford]

TraderTogami #:

Thanks, and to answer your question, Bool2 can produce an error just like any other function. Example: 

bool Bool2(){

int x = 1/0;

int y = 2; 

return x == y;

}

Oh, I see. But it is not really the function producing the error, but bad coding.

[TraderTogami]

Keith Watford #:

Oh, I see. But it is not really the function producing the error, but bad coding.

Yeah, though I have seem some people code functions where bool2 produces an error if bool1 is false (though you can argue this is bad coding as well)

[Dominik Egert]

Here an example, without bad coding:

static int array[];

int arr_size = ArraySize(array);

if( (arr_size > NULL)
 && (Array[arr_size - 1] != NULL) )
{ ... }

[TraderTogami]

Dominik Christian Egert #:

Here an example, without bad coding:

static int array[];

int arr_size = ArraySize(array);

if( (arr_size > NULL)
 && (Array[arr_size - 1] != NULL) )
{ ... }

Very good example, I have done something similar to this in the past.