Using the if statement

Use the if statement when you want to execute a series of statements based on a whether a certain condition is true.

// if statement
if (condition) {
  // statements;
}

There are several times when you'll use if statements when you work on a Flash project. For example, if you are building a Flash site that requires users to log in before they can access certain sections of a website, you can use an if statement to validate that the user enters some text in the username and password fields.

If you need to validate user names and passwords using an external database, you probably want to verify that the username/password combination a user submits matches a record in the database. You also want to check whether the user has permission to access the specified part of the site.

If you script animations in Flash, you might want to use the if statement to test whether an instance on the Stage is still within the boundaries of the Stage. For example, if a ball moves downward along the y-axis, you might need to detect when the ball collides with the bottom edge of the Stage, so you can change the direction so that the ball appears to bounce upwards.

To use an if statement:

  1. Select File > New and then select Flash Document.
  2. Select Frame 1 of the Timeline, and then type the following ActionScript in the Actions panel:
    // create a string to hold AM and PM
    var amPm:String = "AM";
    // no parameters pass to Date, so returns current date/time
    var current_date:Date = new Date();
    // if current hour is greater than/equal to 12, sets amPm string to "PM".
    if (current_date.getHours() >= 12) {
        amPm = "PM";
    }
    trace(amPm);
    
  3. Select Control > Test Movie to test the ActionScript.

    In this code, you create a string that holds AM or PM based on the current time of day. If the current hour is greater than or equal to 12 the amPM string sets to PM. Finally, you trace the amPm string, and if the hour is greater than or equal to 12, PM is displayed. Otherwise, you'll see AM.