Example: Expressions used as if-statement conditions

The condition of an if statement is an expression. How complex the expression is, can have an effect on which CodeXM patterns will match the condition.

In the following snippet of target C/C++ code:

if ( my_boolean ) {
    if ( getPropertyValue(a) == v) {
        // ... Do something.
    }
};

... we see a pair of if statements. The ifStatement pattern detects both instances of if.

But each statement has a condition: namely, the part enclosed by the parentheses that follow the keyword if. Both conditions in this example are expressions. The first is simply a variable reference. The second is more complicated: It is made up of a binary operator (specifically, the equality operator) with operands (which are themselves expressions) appearing on either side. The left-hand operand is a function call, and the right-hand operand is a variable reference.

You could match the first of these conditions by using the expression pattern variableReference (which also matches the right-hand side of the second condition), and you could match the second of these conditions by using the expression pattern binaryOperator.

To inspect a complete condition expression, look at the .conditionExpression property of the ifStatement pattern.