Flash / Flex / ActionScript/Language/Comparison Operators
Содержание
- 1 Checking Equality or Comparing Values
- 2 Comparison Operators in Actionscript
- 3 Equality (==)
- 4 Greater Than (>) and Less Than (
- 5 Not Equal To (!=)
- 6 Number Comparison
- 7 Strict equality
- 8 The logical inequality operator (!=) returns false if two values are equal and true if they aren"t.
- 9 Two composite items are equal only if they both refer to the identical object
- 10 Use the <= and >= operators to check if one value is less than or equal to, or greater than or equal to, another value:
- 11 Use the < and > operators to check if one value is less than or greater than another value:
- 12 When comparing primitive datatypes, ActionScript compares them by value.
- 13 When you compare composite datatypes, ActionScript compares them by reference.
Checking Equality or Comparing Values
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ trace(5 == 6); // Displays: false trace(6 == 6); // Displays: true
} }
}
</source>
Comparison Operators in Actionscript
<source lang="java">
Operator Name == Equals != Not equals > Greater than < Less than >= Greater than or equal <= Less than or equal
</source>
Equality (==)
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){
var weather:String = "rain"; if (weather == "rain") { trace("bringUmbrella"); } } }
}
</source>
Greater Than (>) and Less Than (
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){
var x:int = 0; var a:int = -1; var b:int = 0; var c:int = 1; trace(x <= a); // Displays: false trace(x >= a); // Displays: true trace(x <= b); // Displays: true trace(x >= b); // Displays: true trace(x <= c); // Displays: true trace(x >= c); // Displays: false } }
}
</source>
Not Equal To (!=)
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ var weather:String = "rain"; if (weather != "sun") { trace("bringUmbrella"); } if (!(weather == "sun")) { trace("bringUmbrella"); } } }
}
</source>
Number Comparison
<source lang="java">
Expression Result 6 == 6 true 6 != 6 false 6 > 6 false 6 < 6 false 6 >= 6 true 6 <= 6 true
</source>
Strict equality
<source lang="java">
!== Strict inequality
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ var myVariable:Number = 999; if (myVariable == 4){ trace("if condition true"); } trace(myVariable); } }
}
</source>
The logical inequality operator (!=) returns false if two values are equal and true if they aren"t.
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ trace(5 != 6); // Displays: true trace(6 != 6); // Displays: false } }
}
</source>
Two composite items are equal only if they both refer to the identical object
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ var arrayOne:Array = new Array("a", "b", "c"); var arrayTwo:Array = arrayOne; trace(arrayOne == arrayTwo); // Displays: true
} }
}
</source>
Use the <= and >= operators to check if one value is less than or equal to, or greater than or equal to, another value:
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ trace(5 <= 6); // Displays: true trace(5 >= 5); // Displays: true } }
}
</source>
Use the < and > operators to check if one value is less than or greater than another value:
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ trace(5 < 6); // Displays: true trace(5 > 5); // Displays: false } }
}
</source>
When comparing primitive datatypes, ActionScript compares them by value.
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ var quantity:Number = 6; var total:Number = 6; trace (quantity == total); // Displays: true } }
}
</source>
When you compare composite datatypes, ActionScript compares them by reference.
<source lang="java">
package{
import flash.display.Sprite; public class Main extends Sprite{ public function Main(){ var arrayOne:Array = new Array("a", "b", "c"); var arrayTwo:Array = new Array("a", "b", "c"); trace(arrayOne == arrayTwo); // Displays: false } }
}
</source>