ActionScript 3.0 基本語法
阿新 • • 發佈：2019-01-29
測試環境 Flash CS5; 測試準備:
1、新建 ActionScript 3.0 工程;
2、在第一幀上點選右鍵 -> 動作, 開啟程式碼輸入視窗;
3、輸入程式碼後, Ctrl+Enter 執行.
測試輸出:
變數與常量:
資料型別:
資料型別預設值:
型別轉換:
運算子:
語句:
函式:
錯誤處理:
1、新建 ActionScript 3.0 工程;
2、在第一幀上點選右鍵 -> 動作, 開啟程式碼輸入視窗;
3、輸入程式碼後, Ctrl+Enter 執行.
測試輸出:
trace(123);
trace("abc");
變數與常量:
var a:int, b:int, c:int; a = b = c = 6; trace(a, b, c); //6 6 6 const d:int = 123; trace(d);
資料型別:
//整形 var iV1:int = -1; var iV2:int = new int(-2); var iV3:int = new int("-3"); trace(iV1); trace(iV2); trace(iV3); //無符號整形 var uV1:uint = 1; var uV2:uint = new uint(2); trace(uV1); trace(uV2); //浮點數 var nV1:Number = 3.14159265; var nV2:Number = new Number(-3.14); trace(nV1); trace(nV2); //布林值 var bV1:Boolean = true; var bV2:Boolean = new Boolean(false); trace(bV1); trace(bV2); //字串var sV1:String = 'ActionScript'; var sV2:String = new String("萬一的 Delphi 部落格"); trace(sV1); trace(sV2); /* Object */ //Date var dateVal:Date = new Date(2011, 5, 13); trace(dateVal.toString()); //陣列 var sArr1:Array = ["spring", "summer", "autumn", "winter"]; var sArr2:Array = new Array("spring", "summer", "autumn", "winter"); trace(sArr1[0]); trace(sArr2[1]); var iArr = [11, 22, 33]; trace(iArr[iArr.length-1]); //XML var xmlVal:XML = <List><item>AAA</item><item>BBB</item></List> trace(xmlVal.item[0]); //AAA
資料型別預設值:
//整形 var i:int; trace(i); //0 trace(int.MIN_VALUE, int.MAX_VALUE); //-2147483648 2147483647 //無符號整形 var u:uint; trace(u); //0 trace(uint.MIN_VALUE, uint.MAX_VALUE); //0 4294967295 //浮點數 var n:Number; trace(n); //NaN trace(Number.MIN_VALUE, Number.MAX_VALUE); //4.9406564584124654e-324 1.79769313486231e+308 //布林值 var b:Boolean; trace(b); //false //字串 var s:String; trace(s); //null //Object var obj:Object; trace(obj); //null var dt:Date; trace(dt); //null //未宣告 var arr:Array = [11, 22]; trace(arr[1]); //22 trace(arr[2]); //undefined var val; trace(val); //undefined trace(void); //undefined
型別轉換:
// var i:int; i = int(true); trace(i); //1 i = int(false); trace(i); //0 i = int(5.67); trace(i); //5 i = int(0x1A); trace(i); //26 i = parseInt('3'); trace(i); //3 i = int("4"); trace(i); //4 // var n:Number; n = parseFloat("3.14159265"); trace(n); //3.14159265 n = Number("3.14159265"); trace(n); //3.14159265 // var b:Boolean; b = Boolean(-1); trace(b); //true b = Boolean(0); trace(b); //false b = Boolean(1); trace(b); //true b = Boolean(2); trace(b); //true b = Boolean(""); trace(b); //false b = Boolean(" "); trace(b); //true var obj1:Object; var obj2:Object = new Object(); b = Boolean(obj1); trace(b); //false b = Boolean(obj2); trace(b); //true // var str:String; var arr:Array = ["primary", "secondary", "tertiary"]; str = String(arr); trace(str); //primary,secondary,tertiary str = String(Math.PI); trace(str); //3.141592653589793
運算子:
[] //初始化陣列 {x:y} //初始化物件 () //對錶達式進行分組 f(x) //呼叫函式 new //呼叫建構函式 x.y x[y] //訪問屬性 <></> //初始化 XMLList 物件 (E4X) @ //訪問屬性 (E4X) :: //限定名稱 (E4X) .. //訪問子級 XML 元素 (E4X) ++ //遞增(字首、字尾) -- //遞減(字首、字尾) + //一元 + - //一元 - （非） ! //邏輯 NOT ~ //按位 NOT delete //刪除屬性 typeof //返回型別資訊 void //返回未定義值 * //乘 / //除 % //求模 + //加 - //減 << //按位左移位 >> //按位右移位 >>> //按位無符號右移位 < //小於 > //大於 <= //小於或等於 >= //大於或等於 as //檢查資料型別 in //檢查物件屬性 instanceof //檢查原型鏈 is //檢查資料型別 == //等於 != //不等於 === //全等 !== //不全等 & //按位 AND ^ //按位 XOR | //按位 OR && //邏輯 AND || //邏輯 OR ?: //三目運算子 = //賦值 *= //乘法賦值 /= //除法賦值 %= //求模賦值 += //加法賦值 -= //減法賦值 <<= //按位左移位賦值 >>= //按位右移位賦值 >>>= //按位無符號右移位賦值 &= //按位 AND 賦值 ^= //按位 XOR 賦值 |= //按位 OR 賦值
語句:
//if 語句 if () { } else { } //三目 var a:int, b:int, c:int; a = 1; b = 2; c = (a > b) ? a : b; trace(c); //2 //switch 語句 var dt:Date = new Date(); var day:uint = dt.getDay(); switch(day) { case 0: trace("Sunday"); break; case 1: trace("Monday"); break; case 2: trace("Tuesday"); break; case 3: trace("Wednesday"); break; case 4: trace("Thursday"); break; case 5: trace("Friday"); break; case 6: trace("Saturday"); break; default: trace("Out of range"); break; } //for 迴圈 for (var i:int = 0; i < 5; i++) { trace(i); } //for in 迴圈 var arr:Array = ["one", "two", "three"]; for (var s:String in arr) { trace(s, ":", arr[s]); } /*********** 0 : one 1 : two 2 : three ************/ var obj:Object = {x:20, y:30}; for (var s:String in obj) { trace(s, ":", obj[s]); } /*********** y : 30 x : 20 ************/ //for each 迴圈 var arr:Array = ["one", "two", "three"]; for each (var str in arr) { trace(str); //one/two/three } var obj:Object = {x:20, y:30}; for each (var num in obj) { trace(num); //20/30 } var myXML:XML = <users><fname>Jane</fname><fname>Susan</fname><fname>John</fname></users>; for each (var item in myXML.fname) { trace(item); //Jane/Susan/John } //while 迴圈與 do while 迴圈 var i:int; i = 0; while (i<5) { trace(i); //0/1/2/3/4 i++; } i = 5; do { trace(i); //5 i++; } while(i<5);
函式:
//函式語句 function Add(a:int, b:int):int { return a + b; } trace(Add(1, 2)); //3 //---------------------------------------------------------------- //函式表示式 var traceParameter:Function = function (str:String) { trace("Hello " + str); }; //分號 traceParameter("ActionScript"); //Hello ActionScript //---------------------------------------------------------------- //函式成員 function Sum(a:int, b:int):int { return a+b; } var arr:Array = new Array(); arr[0] = Sum; arr[1] = function(a:int, b:int) { return a*b; }; trace(arr[0](3, 4)); //7 trace(arr[1](3, 4)); //12 //---------------------------------------------------------------- //巢狀函式 function myFun():String { function Fun1():String { return "Hello"; } function Fun2():String { return "ActionScript"; } return Fun1() + " " + Fun2(); } trace(myFun()); //Hello ActionScript //---------------------------------------------------------------- //預設引數 function Sum(a:int, b:int=2, c:int=3):int { return a+b+c; } trace(Sum(1)); //6 //---------------------------------------------------------------- //基本資料型別引數(Boolean、Number、int、uint、String)按值傳遞 function Inc1(a:int):void { a++; } var b:int = 1; Inc1(b); trace(b); //1 //物件引數按引用傳遞 function Inc2(aObj:Object):void { aObj.x++; aObj.y++; } var obj:Object = { x:1, y:2 }; Inc2(obj); trace(obj.x, obj.y); //2 3 //---------------------------------------------------------------- //函式中的 arguments 物件 function myFun(a:int, b:int, c:int):void { for (var i:uint = 0; i< arguments.length; i++) { trace(arguments[i]); } } myFun(11, 22, 33); //11/22/33 //arguments.callee 表示函式本身; 使用回撥完成階乘的例子: var factorial:Function = function (x:uint) { if(x == 0) { return 1; } else { return (x * arguments.callee(x - 1)); //同 return (x * factorial(x - 1)); } } trace(factorial(5)); //120 //---------------------------------------------------------------- //... (rest) 陣列引數: function myFun(...myArgs):void { for (var i:uint = 0; i < myArgs.length; i++) { trace(myArgs[i]); } } myFun(1, 2, 3); //1/2/3 myFun("A", "B", "C", 1, 2, 3); //A/B/C/1/2/3
錯誤處理:
try { throw new Error("丟擲錯誤"); trace("不會執行"); } catch(e:Error) { trace(e.message); } finally { trace("是否發生錯誤都會執行"); }