We have seen throughout this section that digital logic functions can be defined and displayed as either a boolean algebra expression or as a logic gate truth. These decisions are based on boolean expressions boolean expressions that return boolean results: == equal to = not equal an example of an if statement. A boolean expression is a logical statement that is either true or false boolean expressions can compare data of any type as long as both parts of the. A boolean expression involves logical operators which are used to combine conditional expressions together they are also used in assignments (an example.
For input9 to be allowed as a boolean expression, it must result in a bool the compiler disallows x=42, for example, because it assigns x and. An if statement can be followed by an optional else statement, which executes when the boolean expression is false syntax the syntax of an ifthen. The cbool function converts an expression to type boolean returns false a run-time error occurs if the expression can not be interpreted as a numeric value .
Boolean expressions the parenthesized condition of the if statement is a boolean expression in listing 328, the condition is highlighted. 33 boolean expressions an if statement like if(x max) max = x is perhaps deceptively simple conceptually, we say that it checks whether the condition x. The boolean type variables of boolean type have only two values: true and false arithmetic comparisons result in boolean values for example: boolean.
Dim x, y as boolean x = not 23 14 y = not 23 67 ' the preceding statements set x to false and y to true. Boolean logic involves evaluating whether a particular statement is true or false for example the basic operators for boolean expressions are: == (equals), . Strict-boolean-expressions this type is not allowed in the operand for the @ marcind can you provide examples on how it should behave.
For example, arithmetic operators can only be applied to numbers term comparison operators return the boolean value of the expression, true or false. If the operands consist of one boolean expression and one numeric expression, visual basic converts the boolean expression to a numeric. The test can be any expression that evaluates to a boolean value -- true or false so for example, the expression (var 10) evaluates to the value true if var is.