Summary
In this article, you will learn the basics of operators and expressions in MQL5. These are essential building blocks in programming that allow you to work with data, perform calculations, and make logical decisions. We will begin with a general introduction and then explain the different types of operators step by step.
Top Key Takeaways
- Operators are symbols that perform specific operations on data or variables.
- There are arithmetic, logical, comparison, and assignment operators in MQL5.
- Expressions consist of variables, constants, and operators and are used to perform calculations or logical evaluations.
- Understanding operators and expressions is crucial for efficient programming in MQL5.
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What are Operators?
In programming, operators are used to perform calculations or other operations on data. An operator is essentially a symbol that tells the compiler which operation to apply to the data (operands).
Main Types of Operators in MQL5
1. Arithmetic Operators
Arithmetic operators are used to perform mathematical calculations. The most common arithmetic operators in MQL5 are:
- + (Addition): Adds two values.
- - (Subtraction): Subtracts one value from another.
- * (Multiplication): Multiplies two values.
- / (Division): Divides one value by another.
- % (Modulo): Returns the remainder of a division.
Example:
MQL Code
int result = 10 + 5; // Result is 15
2. Assignment Operators
Assignment operators are used to assign a value to an expression or a variable. The most common assignment operator is =.
- = (Assignment): Assigns the value of the right operand to the left variable.
- += (Add and assign): Adds the right value and assigns the result to the left variable.
- -= (Subtract and assign): Subtracts the right value and assigns the result to the left variable.
Example:
MQL Code
int value = 10; // Assigns the value 10
value += 5; // Increases the value by 5 (Result is 15)
3. Comparison Operators
Comparison operators are used to compare two values. They return either true or false depending on whether the comparison is true.
- == (equal): Checks if two values are equal.
- != (not equal): Checks if two values are not equal.
- > (greater than): Checks if the left value is greater than the right.
- < (less than): Checks if the left value is less than the right.
Example:
MQL Code
bool isEqual = (10 == 10); // Result is true
4. Logical Operators
Logical operators are used to combine multiple conditions or perform logical operations. They are useful in control structures like if statements.
- && (logical AND): Returns true if both conditions are true.
- || (logical OR): Returns true if at least one condition is true.
- ! (logical NOT): Negates the value; if the condition is true, false is returned and vice versa.
Example:
MQL Code
bool result = (5 > 3) && (8 > 6); // Result is true
What are Expressions?
An expression is a combination of variables, operators, and values that result in a specific outcome. Expressions are the core of any program as they form the foundation for calculations and decisions.
Example of an Expression:
MQL Code
int result = (10 + 5) * 2; // Expression results in 30
Conclusion
Operators and expressions are indispensable tools in MQL5 programming. They allow you to perform calculations, compare data, and execute logical operations. A solid understanding of these concepts is crucial for writing effective and efficient MQL5 programs.
Questions and Answers
Arithmetic operators are used for mathematical calculations like addition and subtraction, while logical operators are used to evaluate logical conditions.
Yes, you can use multiple operators in an expression. The compiler evaluates them according to operator precedence.
An expression in MQL5 is a combination of variables, constants, operators, and functions that is evaluated to a specific value. For example, an expression could be a mathematical calculation or a logical evaluation.