TypeScript 类型注意事项

1. 变量类型声明定义： var 变量名称：变量类型 = 初始值；枚举类型，初始化的时候注意下标.

enum Color{ Red = 6, Green, Blue = 4};
var colorName: string = Color[7];
var blue:number = Color.Blue;
alert(colorName);
alert(blue);

 var notSure: any = 4; var list any[] = [1, true, "free"];

function warnUser(): void {...}

2. 利用接口实现多态，可选属性用'？'：

interface ILabelledValue {
    lable: string;
}

function printLable(labelledObj: ILabelledValue) {
    alert(labelledObj.lable);
}

var myObj1 = { size: 10, lable: "Size 10 Object" };
printLable(myObj1);
var myObj2 = { index: 1, lable: "Frist size is 10 px" };
printLable(myObj2);

 编译之后的Javascript：

function printLable(labelledObj) {
    alert(labelledObj.lable);
}
var myObj1 = { size: 10, lable: "Size 10 Object" };
printLable(myObj1);
var myObj2 = { index: 1, lable: "Frist size is 10 px" };
printLable(myObj2);
//# sourceMappingURL=greeter.js.map

 发现了吗?加入接口后结构更清晰了。