Expression

From SwinBrain

An expression is an instruction or set of instructions that result in a value of a certain type.

The following are examples of expressions:

Expression Description
10 The integer value 10.
true A Boolean expression.
x > 10 A Boolean expression that will return true if x is larger than 10.
x The value of the x variable, the type is determined by the type of the variable x.
10 + 1 An arithmetic equation resulting in an integer value.
(10 + 1) / 2.5 + 3 * 2.1 An arithmetic equation resulting in a real (or double) value.
GetX() A call to the function GetX, the type of value is determined by the return type of GetX.
x + 10 An arithmetic equation using the variable x. The type of this expression is determined by the type of x.
CalculateArea(radius) A call to the function CalculateArea passing in the parameter radius. The type of this expression is based upon the return type of the CalculateArea function.

Expressions are used within statements. For example

  • The assignment statement in Pascal is variable := expression,
  • In C# an if statement is if(boolean-expression) statement ;

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