MQL4 Reference Language Basics Data Types Integer Types Bool Type

Bool Type

The bool type is intended to store the logical values of true or false, numeric representation of them is 1 or 0, respectively.

Examples:

bool a = true;
bool b = false;
bool c = 1;

The internal representation is a whole number 1 byte large. It should be noted that in logical expressions you can use other integer or real types or expressions of these types - the compiler will not generate any error. In this case, the zero value will be interpreted as false, and all other values - as true.

Examples:

   int i=5;
   double d=-2.5;
   if(i) Print("i = ",i," and is set to true");
   else Print("i = ",i," and is set to false");

   if(d) Print("d = ",d," and has the true value");
   else Print("d = ",d," and has the false value");

   i=0;
   if(i) Print("i = ",i," and has the true value");
   else Print("i = ",i," and has the false value");

   d=0.0;
   if(d) Print("d = ",d," and has the true value");
   else Print("d = ",d," and has the false value");

//--- Execution results
//   i= 5 and has the true value
//   d= -2.5 and has the true value
//   i= 0 and has the false value
//   d= 0 and has the false value