Know about Conditional Statement in Flash - If Statement

A conditional statement is a type of statement that performs an action only when a specified condition is met. The "if" statement is your everyday, all-purpose conditional. If condition has the following syntax:

if (condition)
{
    // write the statements or sub-statements
}

An if statement starts, not surprisingly, with the keyword if. The condition that must be satisfied for substatements to be executed is enclosed in parentheses. The sub-statements are one or more ActionScript statements. Each substatement should be on its own line and terminated with a semicolon. The entire if statement ends with a closing curly brace, (}), without a trailing semicolon.

The condition of our if statement can be any valid expression. When an if statement is executed, the interpreter checks the value of that expression (called the test expression or condition). If it is true, the sub-statements are executed. Otherwise, the sub-statements are not executed. Here is an example;

var a=10;
var b=5

if (a>b)
{
     trace("A is Big"); // This statement will be executed
}

Another form of "if" statement is "If-else". If the condition is true the preceeding sub-statements will be executed. Otherwise, control goes to the else part and executes the sub-statements.

syntax:

if (condition)
{
   sub-statements-1
}
else
{
   sub-statements-2
}

By considering above values of a and b, we can write as below;

if (a>b)
{
     trace("A is Big"); // This statement will be executed
}
else
{
     trace("B is Big"); // This statement will be executed
}

Else If Statement

Using if and else, we can optionally execute one of two code blocks. By using if and else if, we can execute one or even none of an unlimited number of code blocks.

syntax:

if (condition-1)
{
 sub-statements-1
}
else if (condition-2)
{
 sub-statements-2
}
else if (condition-3)
{
 sub-statements-3
}
else
{
 sub-statements-4 // this will be executed, if above conditions were not met
}

where condition-1, condition-2 and condition-3 must be valid expressions. sub-statements-1 will be executed if condition-1 is true. If condition-1 is false, sub-statements-2 will be executed if condition-2 is true. Otherwise, condition-3 is evaluated and so on for as many else if statements are provided. If none of the test expressions are true, the statements in the final else will be executed.

That's all my dear friends. Hope You Enjoyed It!!! Don't forget send mail to me.

"Fundamentals are the Route to the Destination" - BHMK

Go Home