User Guide

54 Chapter 2: ActionScript Basics

Consider the order of operands, especially if you’re setting up complex conditions and you know

how often one condition is true compared with other conditions. In the previous example, if you

know that, in most cases,

i will be greater than 50, consider putting the condition i<50 first; the

condition

i<50 will be checked first, and the second condition doesn’t need to be checked in most

cases.

The following table lists the ActionScript logical operators:

Bitwise operators

Bitwise operators internally manipulate floating-point numbers to change them into 32-bit

integers. The exact operation performed depends on the operator, but all bitwise operations

evaluate each binary digit (bit) of the 32-bit integer individually to compute a new value.

The following table lists the ActionScript bitwise operators:

Equality operators

You can use the equality (

==) operator to determine whether the values or references of two

operands are equal. This comparison returns a Boolean (

true or false) value. If the operands are

strings, numbers, or Boolean values, they are compared by value. If the operands are objects or

arrays, they are compared by reference.

It is a common mistake to use the assignment operator to check for equality. For example, the

following code compares x to 2:

if (x == 2)

In that same example, the expression if (x = 2) would be incorrect, because it doesn’t compare

the operands; it assigns the value of 2 to the variable

Operator Operation performed

Logical AND: Returns true only if both the left and right operands are true.

Logical OR: Returns true if either the left or right operand is true.

!operand Logical NOT: Returns the logical (Boolean) opposite of the operand. The logical NOT

operator takes one operand.

Operator Operation performed

&Bitwise AND

|Bitwise OR

^Bitwise XOR

~Bitwise NOT

<< Shift left

>> Shift right

>>> Shift right zero fill