データ型をãƒã‚§ãƒƒã‚¯ã™ã‚‹ã«ã¯typeof,is,asãªã©ã‚’使ã„ã¾ã™ã€‚
typeof演算å
typeof演算åã¯ãƒ‡ãƒ¼ã‚¿åž‹ã‚’è¡¨ã™æ–‡å—列を返ã—ã¾ã™ã€‚
| データ型 | çµæžœ |
|---|---|
| Array | “object” |
| Boolean | “boolean” |
| Function | “function” |
| int | “number” |
| Number | “number” |
| Object | “object” |
| String | “string” |
| uint | “number” |
| XML | “xml” |
| XMLList | “xml” |
| ユーザー定義クラス㮠インスタンス |
“object” |
var num:int = 14;
var Valentine:Date = new Date();
var str:String = new String("choco");
var flag:Boolean = true;
var girl = new MovieClip();
trace(typeof num); // number
trace(typeof Valentine); // object
trace(typeof str); // string
trace(typeof flag); // boolean
trace(typeof girl); // object
is演算å
is演算åã¯ç‰¹å®šã®ãƒ‡ãƒ¼ã‚¿åž‹ãŒä¸€è‡´ã™ã‚Œã°trueã€ãã†ã§ãªã‘れã°falseã‚’è¿”ã—ã¾ã™ã€‚
ã¾ãŸã€ã‚¯ãƒ©ã‚¹ã®éšŽå±¤æ§‹é€ ã‚’ãƒã‚§ãƒƒã‚¯ã—ã€ãã®ãƒ‡ãƒ¼ã‚¿ãŒç¶™æ‰¿ã™ã‚‹ç¥–å…ˆã®ã‚¯ãƒ©ã‚¹ã‚’指定ã—ãŸå ´åˆã«ã‚‚trueã‚’è¿”ã—ã¾ã™ã€‚
var mySp:Sprite = new Sprite(); trace(mySp is Sprite); // true trace(mySp is DisplayObject); // true trace(mySp is Object); // true
as演算å
A as Bã®ã‚ˆã†ã«è¨˜è¿°ã—ã¾ã™ã€‚AãŒBã§æŒ‡å®šã—ãŸãƒ‡ãƒ¼ã‚¿åž‹ã«ä¸€è‡´ã—ãŸå ´åˆãã®å€¤ã‚’è¿”ã—ã€ä¸€è‡´ã—ãªã„ã¨ãã¯nullã‚’è¿”ã—ã¾ã™ã€‚
var mList:Array = ["January", "February", "March"]; trace(mList as Array); // one,two,three trace(mList as Number); // null trace(mList[2] as int); // null
