MQL4 Reference Language Basics Operators

Operators

Language operators describe some algorithmic operations that must be executed to accomplish a task. The program body is a sequence of such operators. Operators following one by one are separated by semicolons.

Operator	Description
Compound operator {}	One or more operators of any type, enclosed in curly braces {}
Expression operator (;)	Any expression that ends with a semicolon (;)
return operator	Terminates the current function and returns control to the calling program
if-else conditional operator	Is used when it's necessary to make a choice
?: conditional operator	A simple analog of the if-else conditional operator
switch selection operator	Passes control to the operator, which corresponds to the expression value
while loop operator	Performs an operator until the expression checked becomes false. The expression is checked before each iteration
for loop operator	Performs an operator until the expression checked becomes false. The expression is checked before each iteration
do-while loop operator	Performs an operator until the expression checked becomes false. The end condition is checked, after each loop. The loop body is always executed at least once.
break operator	Terminates the execution of the nearest attached external operator switch, while, do-while or for
continue operator	Passes control to the beginning of the nearest external loop operator while, do-while or for
new operator	Creates an object of the appropriate size and returns a descriptor of the created object.
delete operator	Deletes the object created by the new operator

One operator can occupy one or more lines. Two or more operators can be located in the same line. Operators that control over the execution order (if, if-else, switch, while and for), can be nested into each other.

Example:

if(Month() == 12)
if(Day() == 31) Print("Happy New Year!");