- As we mentioned earlier in this lesson, an expression is a phrase—or a collection of variables, numbers, text, and operators—that evaluates to a value. - To the right of the equals sign, you see 6 * 2—this is an expression. - When this script is executed, the expression 6 * 2 is replaced by the result of 6 multiplied by 2, or 12. - An expression can contain variables, arrays, even function calls—anything that, when evaluated, returns a value. - var total:Number = subTotal + tax;. - The value of total is based on the result of adding the variable subTotal to the variable tax. - The expression is subTotal + tax.. - The value of discount is based on the result of multiplying the variable totalPrice by the value of the third element in the employeeDiscount array. - employeeDiscount[2] is the expression.. - the value of japaneseYen is based on the value returned by a call to the convertToYen() function—making the function call itself the expression.. - Expressions enable you to avoid hard-coding values that will remain the same no matter what. - Many of the scripts in this book rely on expressions—that's because without them, your project plays back in exactly the same way each time it's viewed.
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